mfd: intel-lpss: Pass I2C configuration via properties on BXT

I2C host controller need to be configured properly in order to meet I2C
timings specified in the I2C protocol specification. Some Intel Broxton
based machines do not have this information in the ACPI namespace (or the
boot firmware does not support ACPI at all) so we use build-in device
properties instead.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>