or1k: Implement profile hook calling _mcount

or1k: Implement profile hook calling _mcount

Defining this to not abort as found when working on running tests in
the glibc test suite.

We implement this with a call to _mcount with no arguments.  The required
return address's will be pulled from the stack.  Passing the LR (r9) as
an argument had problems as sometimes r9 is clobbered by the GOT logic
in the prologue before the call to _mcount.

gcc/ChangeLog:

	* config/or1k/or1k.h (NO_PROFILE_COUNTERS): Define as 1.
	(PROFILE_HOOK): Define to call _mcount.
	(FUNCTION_PROFILER): Change from abort to no-op.