global: Migrate CONFIG_SH_ETHER_CACHE_WRITEBACK to CFG

Perform a simple rename of CONFIG_SH_ETHER_CACHE_WRITEBACK to CFG_SH_ETHER_CACHE_WRITEBACK

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/include/configs/grpeach.h b/include/configs/grpeach.h
index 5ae17f7..3fde614 100644
--- a/include/configs/grpeach.h
+++ b/include/configs/grpeach.h
@@ -20,7 +20,7 @@
 #define CONFIG_SH_ETHER_USE_PORT	0
 #define CONFIG_SH_ETHER_PHY_ADDR	0
 #define CONFIG_SH_ETHER_PHY_MODE PHY_INTERFACE_MODE_MII
-#define CONFIG_SH_ETHER_CACHE_WRITEBACK
+#define CFG_SH_ETHER_CACHE_WRITEBACK
 #define CFG_SH_ETHER_CACHE_INVALIDATE
 #define CFG_SH_ETHER_ALIGNE_SIZE	64