Add support for 32 and 48 pin variants of RP2350.
Add new `PIO.gpio_base()` method, mirroring the Pico SDK.
Signed-off-by: Phil Howard <phil@gadgetoid.com>
Signed-off-by: Damien George <damien@micropython.org>
All the method signatures from rp2_pio.c and friends have been taken and
converted to RST format, then explanatory notes added for each signature.
Signed-off-by: Tim Radvan <tim@tjvr.org>