i.MX6Q: spl: Fix falcon to use dram_init_banksize

Memory dt node update introduced by spl_fixup_fdt() in below
commit was making DDR configuration in-appropriate
to boot falcon mode. Hence added dram_init_banksize for
explicit assignment of  proper base and size of DDR.

"boot: fdt: Perform arch_fixup_fdt() on the given device tree for falcon boot"
(sha1: 6e7585bb64b12f632681c80c4b193349e1985d92)

Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
diff --git a/arch/arm/mach-imx/spl.c b/arch/arm/mach-imx/spl.c
index 3853e77..258578a 100644
--- a/arch/arm/mach-imx/spl.c
+++ b/arch/arm/mach-imx/spl.c
@@ -15,6 +15,8 @@
 #include <spl.h>
 #include <asm/mach-imx/hab.h>
 
+DECLARE_GLOBAL_DATA_PTR;
+
 #if defined(CONFIG_MX6)
 /* determine boot device from SRC_SBMR1 (BOOT_CFG[4:1]) or SRC_GPR9 register */
 u32 spl_boot_device(void)
@@ -128,3 +130,13 @@
 }
 
 #endif
+
+#if defined(CONFIG_MX6) && defined(CONFIG_SPL_OS_BOOT)
+int dram_init_banksize(void)
+{
+	gd->bd->bi_dram[0].start = CONFIG_SYS_SDRAM_BASE;
+	gd->bd->bi_dram[0].size = imx_ddr_size();
+
+	return 0;
+}
+#endif