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>

MIPS: Kconfig: Rename several firmware related config symbols.

With the upcoming merge of the ARC architecture there is a small likelyhood
of conflicting use for the CONFIG_ARC config symbol. Rename it to
CONFIG_FW_ARC. Also rename CONFIG_ARC32 to CONFIG_FW_ARC32, CONFIG_ARC64
to CONFIG_FW_ARC64.

For consistence also rename CONFIG_SNIPROM to CONFIG_FW_SNIPROM and
CONFIG_CFE to CONFIG_FW_CFE.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

[MIPS] RM: Collected changes

- EISA support for non PCI RMs (RM200 and RM400-xxx). The major part
is the splitting of the EISA and onboard ISA of the RM200, which
makes the EISA bus on the RM200 look like on other RMs.
- 64bit kernel support
- system type detection is now common for big and little endian
- moved sniprom code to arch/mips/fw
- added call_o32 function to arch/mips/fw/lib, which uses a private
stack for calling prom functions
- fix problem with ISA interrupts, which makes using PIT clockevent
possible

Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>