beaglebone: defconfigs: select ext4 as rootfs

Select ext4 as root file system as the genimage config expects ext4 not ext2.
Tested on beaglebone, beagleboneblack and AM335x EVM

[Peter: reworded slightly]
Signed-off-by: Lothar Felten <lothar.felten@gmail.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

configs/beaglebone_defconfig

@@ -12,6 +12,7 @@ BR2_LINUX_KERNEL_DEFCONFIG="omap2plus"
 BR2_LINUX_KERNEL_DTS_SUPPORT=y
 BR2_LINUX_KERNEL_INTREE_DTS_NAME="am335x-evm am335x-bone am335x-boneblack am335x-evmsk"
 BR2_TARGET_ROOTFS_EXT2=y
+BR2_TARGET_ROOTFS_EXT2_4=y
 BR2_TARGET_UBOOT=y
 BR2_TARGET_UBOOT_BUILD_SYSTEM_KCONFIG=y
 BR2_TARGET_UBOOT_CUSTOM_VERSION=y

configs/beaglebone_qt5_defconfig

@@ -25,6 +25,7 @@ BR2_PACKAGE_TI_SGX_DEMOS=y
 BR2_PACKAGE_TI_SGX_KM=y
 BR2_PACKAGE_TI_SGX_UM=y
 BR2_TARGET_ROOTFS_EXT2=y
+BR2_TARGET_ROOTFS_EXT2_4=y
 BR2_TARGET_UBOOT=y
 BR2_TARGET_UBOOT_BUILD_SYSTEM_KCONFIG=y
 BR2_TARGET_UBOOT_CUSTOM_VERSION=y