sh: Fix cache disabling build failures on nommu.

The cache disabling stuff screwed up some of the sh4 nommu
builds, fix it up again.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

arch/sh/mm/Makefile

@@ -4,10 +4,12 @@
 
 obj-y			:= init.o extable.o consistent.o
 
-cache-$(CONFIG_CPU_SH2)		:= cache-sh2.o
-cache-$(CONFIG_CPU_SH3)		:= cache-sh3.o
-cache-$(CONFIG_CPU_SH4)		:= cache-sh4.o pg-sh4.o
-cache-$(CONFIG_CACHE_OFF)	:=
+ifndef CONFIG_CACHE_OFF
+obj-$(CONFIG_CPU_SH2)		+= cache-sh2.o
+obj-$(CONFIG_CPU_SH3)		+= cache-sh3.o
+obj-$(CONFIG_CPU_SH4)		+= cache-sh4.o
+obj-$(CONFIG_SH7705_CACHE_32KB)	+= cache-sh7705.o
+endif
 
 mmu-y			:= tlb-nommu.o pg-nommu.o
 mmu-$(CONFIG_CPU_SH3)	+= fault-nommu.o
@@ -15,19 +17,21 @@ mmu-$(CONFIG_CPU_SH4)	+= fault-nommu.o
 mmu-$(CONFIG_MMU)	:= fault.o clear_page.o copy_page.o tlb-flush.o	\
 			   ioremap.o
 
-obj-y			+= $(cache-y) $(mmu-y)
+obj-y			+= $(mmu-y)
 
 ifdef CONFIG_DEBUG_FS
-obj-$(CONFIG_CPU_SH4)		+= cache-debugfs.o
+obj-$(CONFIG_CPU_SH4)	+= cache-debugfs.o
 endif
 
 ifdef CONFIG_MMU
-obj-$(CONFIG_CPU_SH3)		+= tlb-sh3.o
-obj-$(CONFIG_CPU_SH4)		+= tlb-sh4.o
-obj-$(CONFIG_SH7705_CACHE_32KB) += pg-sh7705.o
+obj-$(CONFIG_CPU_SH3)	+= tlb-sh3.o
+obj-$(CONFIG_CPU_SH4)	+= tlb-sh4.o
+ifndef CONFIG_CACHE_OFF
+obj-$(CONFIG_CPU_SH4)		+= pg-sh4.o
+obj-$(CONFIG_SH7705_CACHE_32KB)	+= pg-sh7705.o
+endif
 endif
 
 obj-$(CONFIG_HUGETLB_PAGE)	+= hugetlbpage.o
-obj-$(CONFIG_SH7705_CACHE_32KB)	+= cache-sh7705.o
 obj-$(CONFIG_32BIT)		+= pmb.o
 obj-$(CONFIG_NUMA)		+= numa.o