media: mexon-ge2d: fixup frames size in registers

The CLIP, SRC & DST registers are coded to take the pixel/line start & end,
starting from 0. Thus the end should be the width/height minus 1.

It can be an issue with clipping and rotation, where it will add spurious
lines from uninitialized or unwanted data with a shift in the result.

Fixes: 59a63532

 ("media: meson: Add M2M driver for the Amlogic GE2D Accelerator Unit")
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>