media: atomisp-ov2680: Move ov2680_init_registers() call to power_up()

Move ov2680_init_registers() call to power_up(), so that we also
init the registers on code-paths which do not call ov2680_s_power()
like running camorama.

Link: https://lore.kernel.org/linux-media/20211107171549.267583-6-hdegoede@redhat.com


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