scripts/mkimg: remove ext2 and ext3 features

ext4 module can handle it.

scripts/mkimg.arm.sh

@@ -55,7 +55,7 @@ profile_rpi() {
 	rpi_firmware_commit="27993e5acf86d1629428ed1a601e86ecd5e5a1df"
 	kernel_flavors="rpi rpi2"
 	kernel_cmdline="dwc_otg.lpm_enable=0 console=ttyAMA0,115200 console=tty1"
-	initrd_features="base bootchart squashfs ext2 ext3 ext4 f2fs kms mmc raid scsi usb"
+	initrd_features="base bootchart squashfs ext4 f2fs kms mmc raid scsi usb"
 	apkovl="genapkovl-dhcp.sh"
 	hostname="rpi"
 	image_ext="tar.gz"
@@ -88,7 +88,7 @@ profile_uboot() {
 	arch="aarch64 armhf armv7"
 	kernel_flavors="vanilla"
 	kernel_addons="xtables-addons"
-	initfs_features="base bootchart squashfs ext2 ext3 ext4 kms mmc raid scsi usb"
+	initfs_features="base bootchart squashfs ext4 kms mmc raid scsi usb"
 	apkovl="genapkovl-dhcp.sh"
 	hostname="alpine"
 	uboot_install="yes"

scripts/mkimg.base.sh

@@ -280,7 +280,7 @@ create_image_targz() {
 profile_base() {
 	kernel_flavors="vanilla"
 	initfs_cmdline="modules=loop,squashfs,sd-mod,usb-storage quiet"
-	initfs_features="ata base bootchart cdrom squashfs ext2 ext3 ext4 mmc raid scsi usb virtio"
+	initfs_features="ata base bootchart cdrom squashfs ext4 mmc raid scsi usb virtio"
 	grub_mod="disk part_gpt part_msdos linux multiboot2 normal configfile search search_label efi_uga efi_gop fat iso9660 cat echo ls test true help gzio"
 	apks="alpine-base alpine-mirrors busybox kbd-bkeymaps chrony e2fsprogs network-extras libressl openssh tzdata"
 	apkovl=