i2c: designware: Switch PCI driver to use i2c_dw_configure_master()

Since we have available helper to configure master mode, let's use it
in the PCI driver instead of spread open-coded variant.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>