arm64: Add CONFIG_DEBUG_SET_MODULE_RONX support

In a similar fashion to other architecture, add the infrastructure
and Kconfig to enable DEBUG_SET_MODULE_RONX support. When
enabled, module ranges will be marked read-only/no-execute as
appropriate.

Signed-off-by: Laura Abbott <lauraa@codeaurora.org>
[will: fixed off-by-one in module end check]
Signed-off-by: Will Deacon <will.deacon@arm.com>

diff --cc arch/arm64/Kconfig.debug
Simple merge

diff --cc arch/arm64/include/asm/cacheflush.h
Simple merge

diff --cc arch/arm64/mm/Makefile
Simple merge

diff --cc arch/arm64/mm/pageattr.c
Simple merge