bus: moxtet: Add spi device table

The moxtet module fails to auto-load on. Add a SPI id table to
allow it to do so.

Signed-off-by: Sjoerd Simons <sjoerd@collabora.com>
Cc:  <stable@vger.kernel.org>
Reviewed-by: Marek Behún <kabel@kernel.org>
Signed-off-by: Gregory CLEMENT <gregory.clement@bootlin.com>