media: ov2740: Fix hts value

HTS must be more then width, so the 1080 value clearly is wrong,
this is then corrected with some weird math dividing clocks in
to_pixels_per_line() which results in the hts getting multiplied by 2,
resulting in 2160.

Instead just directly set hts to the correct value of 2160 and
drop to_pixels_per_line().

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>