rockchip: rk322x: update dram bank size

The DRAM start address is not 0, so need to update the last bank size
as:
DRAM start addr + DRAM_SIZE - last bank start addr

Signed-off-by: Kever Yang <kever.yang@rock-chips.com>
Acked-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
Reviewed-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

arch/arm/mach-rockchip/rk322x-board.c

@@ -72,11 +72,13 @@ int board_init(void)
 
 int dram_init_banksize(void)
 {
-	/* Reserve 0x200000 for OPTEE */
-	gd->bd->bi_dram[0].start = 0x60000000;
+	gd->bd->bi_dram[0].start = CONFIG_SYS_SDRAM_BASE;
 	gd->bd->bi_dram[0].size = 0x8400000;
-	gd->bd->bi_dram[1].start = 0x6a400000;
-	gd->bd->bi_dram[1].size = gd->ram_size - gd->bd->bi_dram[1].start;
+	/* Reserve 0x200000 for OPTEE */
+	gd->bd->bi_dram[1].start = CONFIG_SYS_SDRAM_BASE
+				+ gd->bd->bi_dram[0].size + 0x200000;
+	gd->bd->bi_dram[1].size = gd->bd->bi_dram[0].start
+				+ gd->ram_size - gd->bd->bi_dram[1].start;
 
 	return 0;
 }