Initial mor1kx (OpenRISC) support
Based on milkymist-ng-mor1kx by Stefan Kristiansson
bios: fix boot for or1k
software: factorize exception_handler
targets/mlabs_video: pass with_memtest as kwargs
bios: fill delay slot in boot_helper
sdramphy: remove fixed parameters
gensdrphy: fix memtype and change phase shift in comments.
gensdrphy: fix dm generation