can, tcan4x5x: look to merge rpi support into rpi kernel tree

[Torin Cooper-Bennun]

The Texas Instruments CAN-FD controller, TCAN4550, has kernel support in the tcan4x5x module.

Until a recent patch, Raspberry Pi was unable to utilise the driver, as the module supported only SPI controllers with native 32-bit word support (we only have 8-bit support).

Said patch was merged into net-next in pull request c10b377ff6, which also includes a larger rework of tcan4x5x: https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next.git/commit/?id=c10b377ff670744e1f04f902ff4fe47ea8dd32bd

What's the protocol for merging patches like this into the rpi kernel tree? Are mainline changes the only changes merged in?

Of course in the meantime I can test the patch and hopefully influence development.

I'm fairly new to kernel hacking (or at least, "official" kernel hacking so your patience is appreciated! Thanks.

--- Torin C-B