We used to to handle the driver pitch only for single plan video format.
Add support for multi planes format by re-using the extrapolate function
from the v4l2 element.
Also use this pitch to calculate the proper offsets.
Prevent DRM drivers to pick a slow path if the pitches/offsets don't
match the ones it reported.
https://bugzilla.gnome.org/show_bug.cgi?id=785029
2d67189073