media: ov5640: Remove frame rate check from find_mode()

The current implementation of ov5640_find_mode() fails if the
frame rate programmed with s_frame_interval doesn't match the
maximum frame rate for the current mode.

This causes issues when moving from one mode with higher FPS to another
one which only supports a lower FPS range with tools like media-ctl.

It also forces users that do not use s_frame_interval(), but rather
configure blankings explicitly, to adjust the programmed FPS range to
avoid failures.

For this reason, remove the FPS check from ov5640_find_mode() and only
perform it at s_frame_interval() time.

Signed-off-by: Jacopo Mondi <jacopo@jmondi.org>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>