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.

Change-Id: I0db8372bea6f0e6aba647dd2b471464d5d4bb29a
Signed-off-by: Laura Abbott <lauraa@codeaurora.org>