PICO 2 / RP2350 v1.25.0 DMA funny behaviour

[rikkenharp]

If someone else is using the DMAs in v1.25.0 and having funny behaviour, it's because you have not set ring_sel and ring_size to zero if not needed.
DMAs above 0 have some funny defaults in these two.
Drove me crazy!!!

v1.26.0 preview don't have that problem!

[samneggs]

I had a problem when if not chaining, must set 'chain to' to same channel. My channel 1 was chaining to channel 0 since 0 is default.