arm64: dts: Define big endian of IFC for LS1043a/LS1046a

Integrated flash controller present in LS1043A and LS1046A is big endian.

So add big endian property in the devive tree.

Signed-off-by: Prabhakar Kushwaha <prabhakar.kushwaha@nxp.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>