board/hardkernel/odruidc2: remove rootfs size limit

As resizing the rootfs partition using a partition manager can result
in a non booting image due to the firmware's location, removal of the
size limit for the rootfs allows better match size-wise.

Signed-off-by: Dagg Stompler <daggs@gmx.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

board/hardkernel/odroidc2/genimage.cfg

@@ -34,6 +34,5 @@ image sdcard.img {
 	partition rootfs {
 		partition-type = 0x83
 		image = "rootfs.ext4"
-		size = 512M
 	}
 }