i2c: designware: Disable pm for PMIC i2c-bus even if there is no _SEM method

Cherrytrail devices use the dw i2c-bus with uid 7 to access their PMIC.
Even if the i2c-bus to the PMIC is not shared with the SoC's P-Unit
and i2c-designware-baytrail.c thus does not set the pm_disabled flag,
we still need to disable pm so that ACPI PMIC opregions can access the
PMIC during late-suspend and early-resume.

This fixes errors like these blocking suspend:

  i2c_designware 808622C1:06: timeout waiting for bus ready
  ACPI Exception: AE_ERROR, Returned by Handler for [UserDefinedRegion]
  acpi 80860F14:02: Failed to change power state to D3hot
  PM: late suspend of devices failed

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>