media: ov2680: fix a typo in a function name

All functions in this file starts with 'ov2680_', except ov2860_parse_dt().

This is likely a typo.
rename it to 'ov2680_parse_dt()' (6 and 8)

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>