media: ov5640: Put max framerate into table and simplify check

Currently the various modes are placed into a table, but when
ov5640_find_mode is called, it has to double check whether
or not the requested framerate is tolerated by the mode.
The determination is based on checking hact, vact, and frame rate.

Only 640x480 is allowed at 60fps and QSXGA is limited to 15fps, but
as the number of permitted frame rates change, this will begin to
add more and more complexity to the check.

This patch simplifies the check by adding the max framerate
allowed for each mode into the table of modes.  It then compares
the requested framerate to the max permitted in the mode's table.
This reduces the number of comparisions to one down from three
at run-time.

Signed-off-by: Adam Ford <aford173@gmail.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>