global: Migrate CONFIG_MXC_UART_BASE to CFG

Perform a simple rename of CONFIG_MXC_UART_BASE to CFG_MXC_UART_BASE

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/include/configs/nitrogen6x.h b/include/configs/nitrogen6x.h
index aca15be..5625771 100644
--- a/include/configs/nitrogen6x.h
+++ b/include/configs/nitrogen6x.h
@@ -11,7 +11,7 @@
 
 #include "mx6_common.h"
 
-#define CONFIG_MXC_UART_BASE	       UART2_BASE
+#define CFG_MXC_UART_BASE	       UART2_BASE
 
 /* MMC Configs */
 #define CFG_SYS_FSL_ESDHC_ADDR      0