media: vsp1: Fix offset calculation for plane cropping
The vertical subsampling factor is currently not considered in the
offset calculation for plane cropping done in rpf_configure_partition.
This causes a distortion (shift of the color plane) when formats with
the vsub factor larger than 1 are used (e.g. NV12, see
vsp1_video_formats in vsp1_pipe.c). This commit considers vsub factor
for all planes except plane 0 (luminance).
Drop generalization of the offset calculation to reduce the binary size.