kernel/linux: prepare for arch whose kenel name is not the standard name

For some architectures, the kernel architecture name is not the common
name of the architecture for other tools.

For example: ARM 64-bit is commonly referenced as aarch64, but the kernel
calls it arm64.

Signed-off-by: Michael Hope <michael.hope@linaro.org>
Signed-off-by: Zhenqiang Chen <zhenqiang.chen@linaro.org>
[yann.morin.1998@free.fr: split out of the aarch64 patch]
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>

# MIPS specific config options

## select ARCH_SUPPORTS_32

## select ARCH_SUPPORTS_64 if EXPERIMENTAL

## select ARCH_DEFAULT_32

## select ARCH_USE_MMU

## select ARCH_SUPPORTS_BOTH_ENDIAN

## select ARCH_DEFAULT_BE

## select ARCH_SUPPORTS_WITH_ARCH

## select ARCH_SUPPORTS_WITH_TUNE

## select ARCH_SUPPORTS_WITH_FLOAT

##

## help The MIPS architecture, as defined by:

## help     http://www.mips.com/