i2c: designware-pcidrv: Add 10bit address feature to medfield/merrifield

Both Merrifield TRM and Medfield TRM state:
"Both 7-bit and 10-bit addressing modes are supported."

Signed-off-by: Alexander Stein <alexander.stein@systec-electronic.com>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>