armv8: ls1043aqds: fix to get boot device info from FPGA

The LBMAP switches on the board will tell which boot device is used.
Only QSPI boot is supported if the boot device is IFCCard.

Signed-off-by: Gong Qianyu <Qianyu.Gong@nxp.com>
Reviewed-by: York Sun <york.sun@nxp.com>