Blackfin: bf527-ad7160-eval: fix GPIO CS define

Rather than use a hardcoded "7", use the new Blackfin global define.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>

include/configs/bf527-ad7160-eval.h

@@ -129,7 +129,7 @@
 #define CONFIG_MMC
 #define CONFIG_CMD_EXT2
 #define CONFIG_SPI_MMC
-#define CONFIG_SPI_MMC_DEFAULT_CS (7 + GPIO_PH3)
+#define CONFIG_SPI_MMC_DEFAULT_CS (MAX_CTRL_CS + GPIO_PH3)
 
 
 /*