pyzahl/Gxsm4: Gxsm4 with RPSPMC original GVP stream DMA32 mode

Gxsm4 with RPSPMC original GVP stream DMA32 mode. This is the last stable version supporting RPSPMC with the old DMA32 stream mode. (both prior 2026-03-25 are save) WARNING: every version beyond this tag is experimental and required FPGA/RPSPMC update. Please wait until next stable release pair is announced. The next up version will break DMA and GVP data transfer and requires RPSPMC update to beyond the DSM32 tag. (NOT YET IN GIT)