soc: integrator: Add terminating entry for integrator_cm_match

The of_device_id table is supposed to be zero-terminated.

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>