i2c-designware-pci: use managed functions pcim_* and devm_*

This makes the error handling much more simpler than open-coding everything
and in addition makes the probe function smaller an tidier.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>