The original driver for Silvercrest cameras were using some values that
are different from what datasheet says. As result, it was taken very
less snapshots per second than expected.

A test with the datasheet values showed that they work fine and give a
better frame rate. So, let's stick with datasheet values.
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>