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.
diff --git a/arch/arc/Makefile b/arch/arc/Makefile
index 864adad..aa82d13 100644
--- a/arch/arc/Makefile
+++ b/arch/arc/Makefile
@@ -50,6 +50,9 @@
 
 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