arm64: ftrace: Add CALLER_ADDRx macros

CALLER_ADDRx returns caller's address at specified level in call stacks.
They are used for several tracers like irqsoff and preemptoff.
Strange to say, however, they are refered even without FTRACE.

Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Git-commit: 3711784ece66d39352a0dbb6da40e097a77da057
Git-repo: https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git


[pratikp@codeaurora.org: resolve merge conflicts]

Conflicts:
	arch/arm64/kernel/Makefile

Change-Id: Iae85a00d28ef86d655b94bf1cf583c974d6b1c9b
Signed-off-by: Pratik Patel <pratikp@codeaurora.org>