media: atomisp-ov2680: Push the input_lock taking up into ov2680_s_power()

ov2680_s_power() is the only caller of ov2680_init(), push the input_lock
taking from ov2680_init() up into ov2680_s_power(), this way the new
power_on bool is also protected by it.

Link: https://lore.kernel.org/linux-media/20211107171549.267583-4-hdegoede@redhat.com


Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>