mfd: Add support for several boards to Kontron PLD driver

This patch adds the DMI system ID of the Kontron COMe-bBD#, COMe-bKL6,
COMe-cKL6, COMe-bSL6 and COMe-cAL6 boards to the Kontron PLD driver. The
list of supported products in the module description is also updated.

Signed-off-by: Michael Brunner <michael.brunner@kontron.com>
Acked-by: Christian Rauch <christian.rauch@kontron.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Lee Jones <lee.jones@linaro.org>