arm64: kgdb: handle read-only text / modules

arm64: kgdb: handle read-only text / modules

Handle read-only cases when CONFIG_DEBUG_RODATA (4.0) or
CONFIG_DEBUG_SET_MODULE_RONX (3.18) are enabled by using
aarch64_insn_write() instead of probe_kernel_write() as introduced by
commit 2f896d586610 ("arm64: use fixmap for text patching") in 4.0.

Fixes: 11d91a770f1f ("arm64: Add CONFIG_DEBUG_SET_MODULE_RONX support")
Signed-off-by: AKASHI Takahiro <[email protected]>
Reviewed-by: Mark Rutland <[email protected]>
Cc: Will Deacon <[email protected]>
Cc: Jason Wessel <[email protected]>
Signed-off-by: Catalin Marinas <[email protected]>