linux-imx

dt-binding: spi: Document Macronix controller bindings

Document the bindings used by the Macronix controller.

Signed-off-by: Mason Yang <masonccyang@mxic.com.tw>
Reviewed-by: Boris Brezillon <boris.brezillon@bootlin.com>
Signed-off-by: Mark Brown <broonie@kernel.org>