ARM64: zynqmp: Modify the SD and QSPI bootmode values

Modify the SD bootmode value to 0x3 as per latest
spec. Also add new boot mode QSPI 32 bit boot mode

Signed-off-by: Siva Durga Prasad Paladugu <sivadur@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>