media: cxd2841er: avoid too many status inquires

I2C ops are expensive, as the I2C bus typical speed is 100kbps.

Also, stats reading take some time, as it requires to retrieve a
certain number of packets to complete.

While we don't know the minimal for CXD2841er, trying to do it
too quickly is still a very bad idea.

So, add some sanity logic there, preventing to retrieve stats
faster than one second.

This shouldn't cause any issues with well behavior apps, as they
usually take stats on a polling rate slower than 1 second.

Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: Sean Young <sean@mess.org>