arm64: asm: add CPU_LE & CPU_BE assembler helpers

Add CPU_LE and CPU_BE to select assembler code in little and big
endian configurations respectively.

Signed-off-by: Matthew Leach <matthew.leach@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Git-commit: e68bedaa03c950ae8045e7899e7a6b2a97d1bf41
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git


Signed-off-by: Ian Maund <imaund@codeaurora.org>