Fix GPMC CS2 memory setup at apollon

It disables the current map first

Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
diff --git a/board/apollon/mem.c b/board/apollon/mem.c
index c0edca5..0211c6a 100644
--- a/board/apollon/mem.c
+++ b/board/apollon/mem.c
@@ -198,6 +198,8 @@
 	sdelay(2000);
 
 	/* setup cs2 */
+	__raw_writel(0x0, GPMC_CONFIG7_2);	/* disable current map */
+	sdelay(1000);
 	__raw_writel(APOLLON_24XX_GPMC_CONFIG1_0 | mux | mtype | mwidth,
 		     GPMC_CONFIG1_2);
 	/* It's same as cs 0 */