global: Migrate CONFIG_USART_BASE to CFG

Perform a simple rename of CONFIG_USART_BASE to CFG_USART_BASE

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/include/configs/sam9x60ek.h b/include/configs/sam9x60ek.h
index 27b39eb..800b98f 100644
--- a/include/configs/sam9x60ek.h
+++ b/include/configs/sam9x60ek.h
@@ -14,7 +14,7 @@
 #define CFG_SYS_AT91_SLOW_CLOCK	32768
 #define CFG_SYS_AT91_MAIN_CLOCK	24000000	/* 24 MHz crystal */
 
-#define CONFIG_USART_BASE   ATMEL_BASE_DBGU
+#define CFG_USART_BASE   ATMEL_BASE_DBGU
 #define CONFIG_USART_ID     0 /* ignored in arm */
 
 /*