imx: imx8mp_evk: fix boot issue

The u-boot-spl.bin pad with ddr firmware conflicts with the
CONFIG_MALLOC_F_ADDR area, the ddr firmware will be overwritten
by malloc in SPL stage and cause ddr initialization not able
to finish. So update the related addresses to fix the issue.

Reported-by: Fabio Estevam <festevam@gmail.com>
Signed-off-by: Peng Fan <peng.fan@nxp.com>
Signed-off-by: Fabio Estevam <festevam@gmail.com>
diff --git a/configs/imx8mp_evk_defconfig b/configs/imx8mp_evk_defconfig
index 0693658..17452b6 100644
--- a/configs/imx8mp_evk_defconfig
+++ b/configs/imx8mp_evk_defconfig
@@ -4,7 +4,8 @@
 CONFIG_SPL_GPIO_SUPPORT=y
 CONFIG_SPL_LIBCOMMON_SUPPORT=y
 CONFIG_SPL_LIBGENERIC_SUPPORT=y
-CONFIG_SYS_MALLOC_F_LEN=0x10000
+CONFIG_SYS_MALLOC_F_LEN=0x8000
+CONFIG_SPL_SYS_MALLOC_SIMPLE=y
 CONFIG_ENV_SIZE=0x1000
 CONFIG_ENV_OFFSET=0x400000
 CONFIG_SYS_I2C_MXC_I2C1=y