arm64: dts: zynqmp: Fix nand dt node

DC3 nand node is not correct, it is showing all partitions under
controller node directly. Create two sub nand nodes with partitions for
each.

Signed-off-by: Ashok Reddy Soma <ashok.reddy.soma@amd.com>
Link: https://lore.kernel.org/r/20230224050709.30014-4-ashok.reddy.soma@amd.com


Signed-off-by: Michal Simek <michal.simek@amd.com>