rockchip: Explicitly set CONFIG_SPL_STACK_R_MALLOC_SIMPLE_LEN

Now that u-boot relocates the malloc area in SPL to SDRAM, with the
malloc area sitting below the SPL_STACK_R_ADDR the
SPL_STACK_R_MALLOC_SIMPLE_LEN needs to be set explicitly for
rockchip as its SPL_STACK_R_ADDR (512kb) is smaller then
STACK_R_MALLOC_SIMPLE_LEN (1Mb).

Using the same value as SYS_MALLOC_F_LEN (8kb) is enough to load u-boot
from SD card.
Signed-off-by: NSjoerd Simons <sjoerd.simons@collabora.co.uk>
Acked-by: NSimon Glass <sjg@chromium.org>

configs/chromebook_jerry_defconfig

@@ -4,6 +4,7 @@ CONFIG_SYS_MALLOC_F_LEN=0x2000
 CONFIG_ROCKCHIP_RK3288=y
 CONFIG_TARGET_CHROMEBOOK_JERRY=y
 CONFIG_SPL_STACK_R_ADDR=0x80000
+CONFIG_SPL_STACK_R_MALLOC_SIMPLE_LEN=0x2000
 CONFIG_DEFAULT_DEVICE_TREE="rk3288-jerry"
 CONFIG_SPL_STACK_R=y
 # CONFIG_CMD_IMLS is not set

configs/firefly-rk3288_defconfig

@@ -4,6 +4,7 @@ CONFIG_SYS_MALLOC_F_LEN=0x2000
 CONFIG_ROCKCHIP_RK3288=y
 CONFIG_TARGET_FIREFLY_RK3288=y
 CONFIG_SPL_STACK_R_ADDR=0x80000
+CONFIG_SPL_STACK_R_MALLOC_SIMPLE_LEN=0x2000
 CONFIG_DEFAULT_DEVICE_TREE="rk3288-firefly"
 CONFIG_SPL_STACK_R=y
 # CONFIG_CMD_IMLS is not set