dt-bindings: spi: Add binding for Faraday FTSSP010

dt-bindings: spi: Add binding for Faraday FTSSP010

This adds a binding for the Faraday FTSSP010 SSP controller,
a pretty straight-forward syncronous serial port and SPI
controller.

The bindings are submitted separately because the one device
that has this is using it in a "nonstandard way" with regards
to the electronics, and does not make it possible to develop
or test a proper driver. However we want to be able to add
this resource to the device trees and it's not complex.

Signed-off-by: Linus Walleij <linusw@kernel.org>
Link: https://patch.msgid.link/20260203-gemini-ssp-bindings-v1-1-6d85c9c72371@kernel.org
Signed-off-by: Mark Brown <broonie@kernel.org>