gcc to remove -mapcs-frame which will break perf userspace backtraces on ARM

[Austin Lund]

Using -fomit-frame-pointer with gcc on ARM does not guarantee that the
full frame with the return address is actually pushed onto the stack.
Currently I use -mapcs-frame to achieve this and this allows the code
in perf_callchain.c to generate the right userspace stack traces for
perf.

It seems that gcc have deprecated -mapcs-frame
(https://gcc.gnu.org/ml/gcc-patches/2015-01/msg01001.html)

It isn't clear to me what should replace it.  Any suggestions?