spi/pxa2xx-pci: Add common clock framework support in PCI glue layer

SPI PXA2XX core layer has dependency on common clock framework
to obtain information on host supported clock rate. Thus, we
setup the clock device in the PCI glue layer to enable PCI mode
host pass in the clock rate information.

Signed-off-by: Chew, Chiau Ee <chiau.ee.chew@intel.com>
Acked-by: Kweh, Hock Leong <hock.leong.kweh@intel.com>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Mark Brown <broonie@linaro.org>