OMAPDSS: Apply VENC timings even if panel is disabled

The VENC interfaces uses it's venc_set_timing() function to take in a new set
of timings. If the panel is disabled, it does not disable and re-enable the
interface. Currently, the manager timings are applied in venc_power_on(), these
are not called by set_timings if the panel is disabled. When checking overlay
and manager data, the DSS driver uses the last applied manager timings, and not
the timings held by omap_dss_device struct. Hence, there is a need to apply the
new manager timings even if the panel is disabled.

Apply the manager timings if the VENC panel is disabled.

This is similar to the commit below which fixed the same issue for HDMI/DPI
interfaces:

fcc36619

Signed-off-by: Archit Taneja <archit@ti.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>