configs: fix typo BR2_TARGET_ROOTFS_EXT2_4

The ext4 option is BR2_TARGET_ROOTFS_EXT2_4 not
BR2_TARGET_ROOTFS_EXT_4.

This fixes the new defconfig check.

Signed-off-by: Romain Naour <romain.naour@gmail.com>
Cc: Fabio Estevam <fabio.estevam@nxp.com>
Reviewed-by: Fabio Estevam <festevam@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

configs/freescale_imx28evk_defconfig

@@ -25,7 +25,7 @@ BR2_TARGET_UBOOT_FORMAT_SD=y
 
 # Filesystem
 BR2_TARGET_ROOTFS_EXT2=y
-BR2_TARGET_ROOTFS_EXT4=y
+BR2_TARGET_ROOTFS_EXT2_4=y
 
 # To generate SD Image
 BR2_PACKAGE_HOST_DOSFSTOOLS=y

configs/imx23evk_defconfig

@@ -25,7 +25,7 @@ BR2_TARGET_UBOOT_FORMAT_SD=y
 
 # Filesystem
 BR2_TARGET_ROOTFS_EXT2=y
-BR2_TARGET_ROOTFS_EXT4=y
+BR2_TARGET_ROOTFS_EXT2_4=y
 
 # To generate SD card image
 BR2_PACKAGE_HOST_DOSFSTOOLS=y

configs/olimex_imx233_olinuxino_defconfig

@@ -33,7 +33,7 @@ BR2_PACKAGE_ZD1211_FIRMWARE=y
 
 # Filesystem
 BR2_TARGET_ROOTFS_EXT2=y
-BR2_TARGET_ROOTFS_EXT4=y
+BR2_TARGET_ROOTFS_EXT2_4=y
 # BR2_TARGET_ROOTFS_TAR is not set
 
 # U-Boot