media: cx23885: Set subdev host data to clk_freq pointer

Currently clk_freq is ignored entirely, because the cx235840 driver
configures the xtal at the chip defaults. This is an issue if a
board is produced with a non-default frequency crystal. If clk_freq
is not zero the cx25840 will attempt to use the setting provided,
or fall back to defaults otherwise.

Signed-off-by: Brad Love <brad@nextdimension.cc>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>