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/dart_6ul.h b/include/configs/dart_6ul.h
index c2ed9c7..fb61910 100644
--- a/include/configs/dart_6ul.h
+++ b/include/configs/dart_6ul.h
@@ -28,7 +28,7 @@
 #define MMC_ROOTFS_PART			2
 
 /* Console configs */
-#define CONFIG_MXC_UART_BASE		UART1_BASE
+#define CFG_MXC_UART_BASE		UART1_BASE
 
 /* MMC Configs */