i2c: designware-pci: Switch over to MSI interrupts

Some devices support MSI interrupts. Let's at least try to use them in
platforms that provide MSI capability.

Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>