mfd: arizona-spi: Add missing MODULE_DEVICE_TABLE

This patch adds missing MODULE_DEVICE_TABLE definition
which generates correct modalias for automatic loading
of this driver when it is built as a module.

Fixes: 3f65555c ("mfd: arizona: Split of_match table into I2C and SPI versions")
Signed-off-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Signed-off-by: Lee Jones <lee@kernel.org>
Link: https://lore.kernel.org/r/20230323134138.834369-1-ckeepax@opensource.cirrus.com