armv8: layerscape: Drop u-boot-with-spl.bin for selected boards

armv8: layerscape: Drop u-boot-with-spl.bin for selected boards

For SPL boot with PBL, u-boot-with-spl-pbl.bin is the final image.
Drop unused u-boot-with-spl.bin.

Signed-off-by: York Sun <[email protected]>
CC: Mingkai Hu <[email protected]>
CC: Ruchika Gupta <[email protected]>
CC: Prabhakar Kushwaha <[email protected]>
CC: Udit Agarwal <[email protected]>
CC: Sumit Garg <[email protected]>
CC: Priyanka Jain <[email protected]>