Add ARM_BE8() helper to wrap any code conditional on being
compile when CONFIG_ARM_ENDIAN_BE8 is selected and convert
existing places where this is to use it.
Acked-by: NNicolas Pitre <nico@linaro.org>
Reviewed-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NBen Dooks <ben.dooks@codethink.co.uk>