ARM: rework endianess selection

Choosing big-endian vs little-endian kernels in Kconfig has not worked
correctly since the introduction of CONFIG_ARCH_MULTIPLATFORM a long
time ago.

The problems is that CONFIG_BIG_ENDIAN depends on
ARCH_SUPPORTS_BIG_ENDIAN, which can set by any one platform
in the config, but would actually have to be supported by all
of them.

This was mostly ok for ARMv6/ARMv7 builds, since these are BE8 and
tend to just work aside from problems in nonportable device drivers.
For ARMv4/v5 machines, CONFIG_BIG_ENDIAN and CONFIG_ARCH_MULTIPLATFORM
were never set together, so this was disabled on all those machines
except for IXP4xx.

As IXP4xx can now become part of ARCH_MULTIPLATFORM, it seems better to
formalize this logic: all ARMv4/v5 platforms get an explicit dependency
on being either big-endian (ixp4xx) or little-endian (the rest). We may
want to fix ixp4xx in the future to support both, but it does not work
in LE mode at the moment.

For the ARMv6/v7 platforms, there are two ways this could be handled

a) allow both modes only for platforms selecting
'ARCH_SUPPORTS_BIG_ENDIAN' today, but only LE mode for the
others, given that these were added intentionally at some
point.

b) allow both modes everwhere, given that it was already possible
to build that way by e.g. selecting ARCH_VIRT, and that the
list is not an accurate reflection of which platforms may or
may not work.

Out of these, I picked b) because it seemed slighly more logical
to me.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>

ARM: npcm: wpcm450: select interrupt controller driver

The interrupt controller driver is necessary in order to have a
functioning Linux system on WPCM450. Select it in mach-npcm/Kconfig.

Fixes: ece3fe93e8f4 ("ARM: npcm: Introduce Nuvoton WPCM450 SoC")
Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Link: https://lore.kernel.org/r/20210513165627.1767093-1-j.neuschaefer@gmx.net
Link: https://lore.kernel.org/r/20210518071514.604492-1-joel@jms.id.au'
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

ARM: npcm: Introduce Nuvoton WPCM450 SoC

The WPCM450 is an older BMC SoC in the Nuvoton NPCM family, originally
marketed as Winbond WPCM450.

Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Link: https://lore.kernel.org/r/20210406120921.2484986-6-j.neuschaefer@gmx.net
Signed-off-by: Joel Stanley <joel@jms.id.au>

ARM: npcm: Bring back GPIOLIB support

The CONFIG_ARCH_REQUIRE_GPIOLIB is gone since commit 65053e1a7743
("gpio: delete ARCH_[WANTS_OPTIONAL|REQUIRE]_GPIOLIB") and all platforms
should explicitly select GPIOLIB to have it.

Link: https://lore.kernel.org/r/20200130195525.4525-1-krzk@kernel.org
Cc: <stable@vger.kernel.org>
Fixes: 65053e1a7743 ("gpio: delete ARCH_[WANTS_OPTIONAL|REQUIRE]_GPIOLIB")
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Olof Johansson <olof@lixom.net>

treewide: Add SPDX license identifier - Makefile/Kconfig

Add SPDX license identifiers to all Make/Kconfig files which:

- Have no license information of any form

These files fall under the project license, GPL v2 only. The resulting SPDX
license identifier is:

GPL-2.0-only

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

arm: npcm: modify configuration for the NPCM7xx BMC.

Modify configuration and MakeFile
for the Nuvoton NPCM and NPCM7xx BMC.

[arnd: took this one late, since it fixes some build problems
with the original commit]

Signed-off-by: Tomer Maimon <tmaimon77@gmail.com>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

arm: npcm: add basic support for Nuvoton BMCs

Adds basic support for the Nuvoton NPCM750 BMC.

Signed-off-by: Brendan Higgins <brendanhiggins@google.com>
Reviewed-by: Tomer Maimon <tmaimon77@gmail.com>
Reviewed-by: Avi Fishman <avifishman70@gmail.com>
Tested-by: Tomer Maimon <tmaimon77@gmail.com>
Tested-by: Avi Fishman <avifishman70@gmail.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>