ARM: SPL: Move gpmc_init() to spl_board_init()

This is an OMAP/related-specific function, move calling it to
spl_board_init() and turn on CONFIG_SPL_BOARD_INIT on the boards that
enabled NAND and didn't enable this already.

Signed-off-by: Tom Rini <trini@ti.com>
diff --git a/arch/arm/cpu/armv7/omap-common/boot-common.c b/arch/arm/cpu/armv7/omap-common/boot-common.c
index 3406cfb..ed398fd 100644
--- a/arch/arm/cpu/armv7/omap-common/boot-common.c
+++ b/arch/arm/cpu/armv7/omap-common/boot-common.c
@@ -49,6 +49,13 @@
 	return omap_bootmode;
 }
 
+void spl_board_init(void)
+{
+#ifdef CONFIG_SPL_NAND_SUPPORT
+	gpmc_init();
+#endif
+}
+
 int board_mmc_init(bd_t *bis)
 {
 	switch (spl_boot_device()) {