mfd: Add MODULE_DEVICE_TABLE to mc13xxx-core

The device table is required to load modules based on modaliases.
After adding the MODULE_DEVICE_TABLE, below entries will be added to
modules.alias:
alias spi:mc13892 mc13xxx_core
alias spi:mc13783 mc13xxx_core

Signed-off-by: Axel Lin <[e-mail]>
Acked-by: Uwe Kleine-König <[e-mail]>
Signed-off-by: Samuel Ortiz <[e-mail]>

drivers/mfd/mc13xxx-core.c

···
 		/* sentinel */
 	}
 };
+MODULE_DEVICE_TABLE(spi, mc13xxx_device_id);
 
 static struct spi_driver mc13xxx_driver = {
 	.id_table = mc13xxx_device_id,