wilc1000: Add id_table to spi_driver

This eliminates warning message:

	SPI driver WILC_SPI has no spi_device_id for microchip,wilc1000

and makes device-tree autoloading work.

Signed-off-by: David Mosberger-Tang <davidm@egauge.net>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://lore.kernel.org/r/20211202045001.2901903-1-davidm@egauge.net