MIPS: IP28: Change to build with -mr10k-cache-barrier=store

Richard Sandiford's new code for inserting the cache-barriers, for GCC
4.3 and above and already incorporated in the current GCC-release, uses
a slightly different option-syntax.
Signed-off-by: Npeter fuerst <post@pfrst.de>
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

arch/mips/Makefile

@@ -473,12 +473,12 @@ endif
 # Simplified: what IP22 does at 128MB+ in ksegN, IP28 does at 512MB+ in xkphys
 #
 ifdef CONFIG_SGI_IP28
-  ifeq ($(call cc-option-yn,-mr10k-cache-barrier=1), n)
-      $(error gcc doesn't support needed option -mr10k-cache-barrier=1)
+  ifeq ($(call cc-option-yn,-mr10k-cache-barrier=store), n)
+      $(error gcc doesn't support needed option -mr10k-cache-barrier=store)
   endif
 endif
 core-$(CONFIG_SGI_IP28)		+= arch/mips/sgi-ip22/
-cflags-$(CONFIG_SGI_IP28)	+= -mr10k-cache-barrier=1 -I$(srctree)/arch/mips/include/asm/mach-ip28
+cflags-$(CONFIG_SGI_IP28)	+= -mr10k-cache-barrier=store -I$(srctree)/arch/mips/include/asm/mach-ip28
 load-$(CONFIG_SGI_IP28)		+= 0xa800000020004000
 
 #