V4L/DVB (5993): cx25840: resetting also requires reloading the firmware

Resetting without reloading the firmware is not enough. Sometimes the
firmware is 'stuck' and needs to be reloaded.

Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>