Use PROFILE_HOOK to add mcount library calls in each toolchain.

gcc/
xxxx-xx-xx  Claudiu Zissulescu  <claziss@synopsys.com>

	* config/arc/arc.h (FUNCTION_PROFILER): Redefine to empty.
	* config/arc/elf.h (PROFILE_HOOK): Define.
	* config/arc/linux.h (PROFILE_HOOK): Likewise.

From-SVN: r266068