Add Zephyr board defs for Raspberry Pi Picos

[tannewt]

Add board defs for rpi_pico_zephyr, rpi_pico_w_zephyr, rpi_pico2_zephyr, and rpi_pico2_w_zephyr. Flash partitions (NVM at 0x180000, CircuitPy at 0x181000) match the native raspberrypi port so users can switch between ports without reformatting.

Also enable MICROPY_NLR_THUMB_USE_LONG_JUMP for the Zephyr port to fix Cortex-M0+ linker relocation errors in nlr_push.

Devices should enumerate but may have bugs after that. These board definitions are meant to make it easier to test the current state of the Zephyr port.

I started to debug the wifi scan but decided not to dig further. So, there are a couple small wifi related changes.

[dhalbert]

Looks fine.

These per-board .conf and .overlay files: is there a way to factor out the common parts? If, say, we wanted to change the partition stuff on all the RP2350 boards, there would be many to change.

[tannewt]

These per-board .conf and .overlay files: is there a way to factor out the common parts? If, say, we wanted to change the partition stuff on all the RP2350 boards, there would be many to change.

.overlay is pretty easy because we can #include other files. .conf is trickier I think because we'd need to add some CMake code to do it.

I'm planning to follow up with a bootloader and partition scheme that can do this factoring out for partitions. I may actually do it in a separate repo so that it is shared amongst all zephyr based Adafruit projects.