NFC: pn544: Pass hardware variant information when downloading firmware

Different pn544 hardware variant may use different commands to download
new firmwares. The C2 does a regular firmware download while the C3 uses
a more secure protocol.
As a consequence we need to pass the hardware variant from the HCI SW
version command reply down to the pn544 i2c layer, in order to use the
right protocol at run time.

Signed-off-by: Arron Wang <arron.wang@intel.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>