media: ov5640: fix auto controls values when switching to manual mode

When switching from auto to manual mode, V4L2 core is calling
g_volatile_ctrl() in manual mode in order to get the manual initial value.
Remove the manual mode check/return to not break this behaviour.

Signed-off-by: Hugues Fruchet <hugues.fruchet@st.com>
Tested-by: Jacopo Mondi <jacopo@jmondi.org>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>