Introduce basic aarch64 instruction decoding helper
aarch64_get_insn_class() and aarch64_insn_hotpatch_safe().
Reviewed-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NJiang Liu <liuj97@gmail.com>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>