i2c: designware-pci: Add support for Elkhart Lake PSE I2C

Add support for Intel(R) Programmable Services Engine (Intel(R) PSE) I2C
controller in Intel Elkhart Lake when interface is assigned to the host
processor.

Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>