trustfence-initramfs-init: clean mount rootfs warnings

Get filesystem type of rootfs block device and pass it explicitly to the
mount command to clean following warnings on boot:

EXT4-fs (dm-0): couldn't mount as ext3 due to feature incompatibilities
EXT4-fs (dm-0): couldn't mount as ext2 due to feature incompatibilities

Signed-off-by: Javier Viguera <javier.viguera@digi.com>

meta-digi-dey/recipes-core/trustfence/trustfence-initramfs/trustfence-initramfs-init

@@ -58,7 +58,8 @@ wipe -cfs ${TMP_KEYFILE}
 
 # Mount mapped device
 mkdir -p /newroot
-mount ${root} /newroot
+FSTYPE="$(blkid ${root} | sed -e 's,.*TYPE="\([^"]\+\)".*,\1,g')"
+mount ${FSTYPE:+-t ${FSTYPE}} ${root} /newroot
 
 #
 # Clean-up and do the switch_root to the final rootfs