[media] cx88: don't pollute the kernel log

There is no reason to dump the sram code to the kernel log when you
stop streaming. Remove those calls to cx88_sram_channel_dump.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>