Vitis project code can only test the SF3 flash up to 128 Mbits

[timothystotts]

Vitis project code can only test the SF3 flash up to 128 Mbits due to a limitation of Serial Flash Commands accepted by the AXI QSPI driver in the IPI-BD. The SF3 flash is actually 256 Mbits in size. There is a possibility that the method by which to access the upper 1/2 of the flash has been overlooked by the project author; but the AXI QSPI driver does not appear to accept 4-byte address commands (it only accepts 3-bytes of address space).