[media] xc5000: support 32MHz & 31.875MHz xtal using the 41.024.5 firmware

Rather than loading firmware specific for the xtal frequency, just use
the standard firmware and set the xtal frequency after firmware upload.

The modified firmware will never be released, so we're better off
merging this now rather than waiting for v3.5.

Signed-off-by: Michael Krufky <mkrufky@kernellabs.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>