Replace our experimental configs with the board config(s) from the (as yet unmerged) Pico 2 W changes branch.
Pico 2 / Pico 2B: Change to match upstream RPI_PICO2 Pico Plus 2: Allocate 2MB to firmware Tiny 2350: Allocate 2MB to firmware Plasma 2350: Allocate 2MB to firmware