pinctrl: raspberrypi: rp2350: Add support for RP2350X

A significant amount of the pin muxing is duplicated between the RP2040,
the RP2350A, and RP2350B. Reflect this in the file structure, with a
`-common` suffix used to to indicate this.

Macros are defined in ascending order of the function index in the
relevant table in the datasheet. SoC/SoC-series specific macros are
defined in their respective tables. Functions that are not currently
used (e.g. the new HSTX) are intentionally not defined here as they do
not (currently) have any use in the Zephyr tree (i.e. there's no drivers
that make use of this functionality).

clang-format has been run over the existing definitions to reduce the
noise generated by CI. These are cosmetic changes; I've tried to retain
attribution to the relevant authors where applicable.

Signed-off-by: Andrew Featherstone <andrew.featherstone@gmail.com>