frv: Remove redundant debugging info flag

The generic makefile now sets '-Wa,--gdwarf2' in KBUILD_AFLAGS, so
this setting is no longer needed in arch makefiles.

Also remove a commented out addition of a -O1 to KBUILD_CFLAGS, and
comment text relating to these removed lines.

Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Geoff Levand <geoff@infradead.org> for Huawei, Linaro
Signed-off-by: Michal Marek <mmarek@suse.cz>

arch/frv/Makefile

@@ -74,13 +74,6 @@ KBUILD_CFLAGS	+= -mno-fdpic -mgpr-32 -msoft-float -mno-media
 KBUILD_CFLAGS	+= -ffixed-fcc3 -ffixed-cc3 -ffixed-gr15 -ffixed-icc2
 KBUILD_AFLAGS	+= -mno-fdpic
 
-# make sure the .S files get compiled with debug info
-# and disable optimisations that are unhelpful whilst debugging
-ifdef CONFIG_DEBUG_INFO
-#KBUILD_CFLAGS	+= -O1
-KBUILD_AFLAGS	+= -Wa,--gdwarf2
-endif
-
 head-y		:= arch/frv/kernel/head.o
 
 core-y		+= arch/frv/kernel/ arch/frv/mm/