imx8mp_rsb3720a1: Enable cache in SPL

There is no reason for disabling I-cache and D-cache
in SPL.

Remove the unneeded CONFIG_SPL_SYS_ICACHE_OFF and
CONFIG_SPL_SYS_DCACHE_OFF options.

Signed-off-by: Fabio Estevam <festevam@denx.de>
diff --git a/configs/imx8mp_rsb3720a1_4G_defconfig b/configs/imx8mp_rsb3720a1_4G_defconfig
index a7585ba..d7f1aa0 100644
--- a/configs/imx8mp_rsb3720a1_4G_defconfig
+++ b/configs/imx8mp_rsb3720a1_4G_defconfig
@@ -1,6 +1,4 @@
 CONFIG_ARM=y
-CONFIG_SPL_SYS_ICACHE_OFF=y
-CONFIG_SPL_SYS_DCACHE_OFF=y
 CONFIG_ARCH_IMX8M=y
 CONFIG_SYS_TEXT_BASE=0x40200000
 CONFIG_SYS_MALLOC_LEN=0x2000000
diff --git a/configs/imx8mp_rsb3720a1_6G_defconfig b/configs/imx8mp_rsb3720a1_6G_defconfig
index 5d06dc4..7ceac2b 100644
--- a/configs/imx8mp_rsb3720a1_6G_defconfig
+++ b/configs/imx8mp_rsb3720a1_6G_defconfig
@@ -1,6 +1,4 @@
 CONFIG_ARM=y
-CONFIG_SPL_SYS_ICACHE_OFF=y
-CONFIG_SPL_SYS_DCACHE_OFF=y
 CONFIG_ARCH_IMX8M=y
 CONFIG_SYS_TEXT_BASE=0x40200000
 CONFIG_SYS_MALLOC_LEN=0x2000000