arm64: dts: agilex/stratix10: Updated QSPI Flash layout for UBIFS

Non-UBIFS related boot and fpga data should be stored in qspi_boot (mtd0)
while keeping the rootfs with UBIFS in the root partition "mtd1".
Thus, update the QSPI flash layout to support UBIFS in the mtd root
partition.

Signed-off-by: Alif Zakuan Yuslaimi <alif.zakuan.yuslaimi@intel.com>
Signed-off-by: Kah Jing Lee <kah.jing.lee@intel.com>
Signed-off-by: Dinh Nguyen <dinguyen@kernel.org>