warp7: Pass the UART base definition

Since commit 5d69269d ("mx7dsabresd: Define serial port locally")
we need to specify the UART base address in each board config
file, so do this to avoid a build error.
Signed-off-by: NFabio Estevam <fabio.estevam@nxp.com>

include/configs/warp7.h

@@ -14,6 +14,8 @@
 
 #define PHYS_SDRAM_SIZE			SZ_512M
 
+#define CONFIG_MXC_UART_BASE		UART1_IPS_BASE_ADDR
+
 #define CONFIG_BOARD_EARLY_INIT_F
 
 /* MMC Config*/