configs/stm32mp157: remove extra metadata_csum mkfs option

Since commit [1] in U-Boot upstrea, there is no necessity to pass extra
metadata_csum option due to changed env location in U-Boot so we can
drop it completely.

[1] 76db1681da52342ca9f4fb7e6787bd83cc82f429:
stm32mp1: use a specific SD/eMMC partition for U-Boot enviromnent

Signed-off-by: Bartosz Bilas <b.bilas@grinn-global.com>
[yann.morin.1998@free.fr: 76db1681d referecnes a U-Boot commit]
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>

configs/stm32mp157a_dk1_defconfig

@@ -15,7 +15,6 @@ BR2_LINUX_KERNEL_INSTALL_TARGET=y
 BR2_TARGET_ROOTFS_EXT2=y
 BR2_TARGET_ROOTFS_EXT2_4=y
 BR2_TARGET_ROOTFS_EXT2_SIZE="120M"
-BR2_TARGET_ROOTFS_EXT2_MKFS_OPTIONS="-O ^metadata_csum"
 # BR2_TARGET_ROOTFS_TAR is not set
 BR2_TARGET_UBOOT=y
 BR2_TARGET_UBOOT_BUILD_SYSTEM_KCONFIG=y

configs/stm32mp157c_dk2_defconfig

@@ -15,7 +15,6 @@ BR2_LINUX_KERNEL_INSTALL_TARGET=y
 BR2_TARGET_ROOTFS_EXT2=y
 BR2_TARGET_ROOTFS_EXT2_4=y
 BR2_TARGET_ROOTFS_EXT2_SIZE="120M"
-BR2_TARGET_ROOTFS_EXT2_MKFS_OPTIONS="-O ^metadata_csum"
 # BR2_TARGET_ROOTFS_TAR is not set
 BR2_TARGET_UBOOT=y
 BR2_TARGET_UBOOT_BUILD_SYSTEM_KCONFIG=y