Revert "ARC: build: retire old toggles"

This has caused a bunch of build failures at a few sites, with GNU
2015.12 and older as the assembler seems to need -mlock to be able to
grok llock/scond instructions for ARC700 builds.
different places since the
older tools still seem to release
of tools which most people are using seem to trip with the -mlock flag
not being passed.

This reverts commit c3005475889c7c730638f95d13be3360f0b33e98.

arch/arc/Makefile

@@ -50,6 +50,9 @@ atleast_gcc44 :=  $(call cc-ifversion, -ge, 0404, y)
 
 cflags-$(atleast_gcc44)			+= -fsection-anchors
 
+cflags-$(CONFIG_ARC_HAS_LLSC)		+= -mlock
+cflags-$(CONFIG_ARC_HAS_SWAPE)		+= -mswape
+
 ifdef CONFIG_ISA_ARCV2
 
 ifndef CONFIG_ARC_HAS_LL64