[MIPS] Enable SCHED_NO_NO_OMIT_FRAME_POINTER for MIPS.

MIPS get_wchan() no longer requires -fno-omit-frame-pointer.
Signed-off-by: NAtsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

arch/mips/Kconfig

@@ -816,6 +816,10 @@ config GENERIC_CALIBRATE_DELAY
 	bool
 	default y
 
+config SCHED_NO_NO_OMIT_FRAME_POINTER
+	bool
+	default y
+
 #
 # Select some configuration options automatically based on user selections.
 #