[U-Boot] SYS_VENDOR for sr1500 board?

[Dinh Nguyen]

Hi Stefan,

I'm doing a bit of clean up with duplicate CONFIG_* options that
scattered throughout all the socfpga_*hw*.h configs. I noticed that the
sr1500 board is missing a SYS_VENDOR option. Do you know who is the
vendor for this board?

Thanks,
Dinh