V4L/DVB (6652): xc2028: try non-8MHZ init1 firmware

When loading init1 firmware, there may not be an 8MHz specific version.
Load the non-8MHz version if it exists.

Signed-off-by: Chris Pascoe <c.pascoe@itee.uq.edu.au>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>