rockchip: sdram: fix dram_init_banksize

Currently 2.5 GB is calculated as DRAM size for a 1 GB RK322x board
if CONFIG_SPL_OPTEE is set. This is troublesome when booting a
linux kernel since this size will be injected in FDT of the kernel.

gd->bd->bi_dram[0].start (which is basically CONFIG_SYS_SDRAM_BASE)
must not be taken into consideration for calculation of second bank
size, since this offset is already included in calculation of "top".

After applying this patch 992 MB (1024 MB - 32 MB reserved for
optee-os) is correctly calculated and has also been verified on
2 GB boards.

Signed-off-by: Alex Bee <knaerzche@gmail.com>
Reviewed-by: Kever Yang <kever.yang@rock-chips.com>
diff --git a/arch/arm/mach-rockchip/sdram.c b/arch/arm/mach-rockchip/sdram.c
index 24fe6cc..4c637b7 100644
--- a/arch/arm/mach-rockchip/sdram.c
+++ b/arch/arm/mach-rockchip/sdram.c
@@ -56,16 +56,14 @@
 					- CONFIG_SYS_SDRAM_BASE;
 		gd->bd->bi_dram[1].start = tos_parameter->tee_mem.phy_addr +
 					tos_parameter->tee_mem.size;
-		gd->bd->bi_dram[1].size = gd->bd->bi_dram[0].start
-					+ top - gd->bd->bi_dram[1].start;
+		gd->bd->bi_dram[1].size = top - gd->bd->bi_dram[1].start;
 	} else {
 		gd->bd->bi_dram[0].start = CONFIG_SYS_SDRAM_BASE;
 		gd->bd->bi_dram[0].size = 0x8400000;
 		/* Reserve 32M for OPTEE with TA */
 		gd->bd->bi_dram[1].start = CONFIG_SYS_SDRAM_BASE
 					+ gd->bd->bi_dram[0].size + 0x2000000;
-		gd->bd->bi_dram[1].size = gd->bd->bi_dram[0].start
-					+ top - gd->bd->bi_dram[1].start;
+		gd->bd->bi_dram[1].size = top - gd->bd->bi_dram[1].start;
 	}
 #else
 	gd->bd->bi_dram[0].start = CONFIG_SYS_SDRAM_BASE;