ARM: s3c24xx: remove support for ISA drivers on BAST PC/104

BAST is the one machine that theoretically supports unmodified ISA
drivers for hardware on its PC/104 connector, using a custom version of
the inb()/outb() and inw()/outw() macros.

This is incompatible with the generic version used in asm/io.h, and
can't easily be used in a multiplatform kernel.

Removing the special case for 16-bit I/O port access on BAST gets us
closer to multiplatform, at the expense of any PC/104 users with 16-bit
cards having to either use an older kernel or modify their ISA drivers
to manually ioremap() the area and use readw()/write() in place of
inw()/outw(). Either way is probably ok, given that there is a
recurring discussion about dropping s3c24xx altogether, and many
traditional ISA drivers are already gone.

Machines other than BAST already have no support for ISA drivers, though a
couple of them do map one of the external chip-selects into the ISA port
range, using the same address for 8-bit and 16-bit I/O. It is unlikely
that anything actually uses this mapping, but it's also easy to keep
this working by mapping it to the normal platform-independent PCI I/O
base that is otherwise unused on s3c24xx.

The mach/map-base.h file is no longer referenced in global headers and
can be moved into the platform directory.

Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

ARM: s3c: make headers local if possible

A lot of header files are only used internally now, so they can be moved
to mach-s3c, out of the visibility of drivers.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/20200806182059.2431-40-krzk@kernel.org
[krzk: Rebase and fixup leds-s3c24xx driver]
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>