m68knommu: support ColdFire caches that do copyback and write-through

The version 3 and version 4 ColdFire cache controllers support both
write-through and copy-back modes on the data cache. Allow for Kconfig
time configuration of this, and set the cache mode appropriately.

Signed-off-by: Greg Ungerer <gerg@uclinux.org>
diff --git a/arch/m68k/include/asm/m54xxacr.h b/arch/m68k/include/asm/m54xxacr.h
index 6bce82f..29d4713 100644
--- a/arch/m68k/include/asm/m54xxacr.h
+++ b/arch/m68k/include/asm/m54xxacr.h
@@ -73,7 +73,11 @@
 #else
 #define CACHE_MODE (CACR_DEC+CACR_DESB+CACR_DDCM_P+CACR_BEC+CACR_IEC+CACR_EUSP)
 #endif
+#if defined(CONFIG_CACHE_COPYBACK)
+#define DATA_CACHE_MODE (ACR_ENABLE+ACR_ANY+ACR_CM_CP)
+#else
 #define DATA_CACHE_MODE (ACR_ENABLE+ACR_ANY+ACR_CM_WT)
+#endif
 #define INSN_CACHE_MODE (ACR_ENABLE+ACR_ANY)
 
 #define CACHE_INIT	(CACR_DCINVA+CACR_BCINVA+CACR_ICINVA)