ARMV7: Add basic gpmc initialization for OMAP4

This patch adds a gpmc_init function for OMAP4 and adds calls to
gpmc_init for existing OMAP4 boards: panda and sdp4430

Signed-off-by: Steve Sakoman <steve@sakoman.com>
Signed-off-by: Sandeep Paulraj <s-paulraj@ti.com>
diff --git a/board/ti/panda/panda.c b/board/ti/panda/panda.c
index 46a5d1d..917bbec 100644
--- a/board/ti/panda/panda.c
+++ b/board/ti/panda/panda.c
@@ -37,6 +37,8 @@
  */
 int board_init(void)
 {
+	gpmc_init();
+
 	gd->bd->bi_arch_number = MACH_TYPE_OMAP4_PANDA;
 	gd->bd->bi_boot_params = (0x80000000 + 0x100); /* boot param addr */