OMAPDSS: analog-tv-connector: compile fix

connector-analog-tv.c uses omap_dss_pal_timings, defined in omapdss's
venc.c, for default timings. omap_dss_pal_timings only exists when VENC
is enabled in the kernel config, so disabling VENC breaks
omap_dss_pal_timings connector-analog-tv compilation.

Instead of adding dependency to VENC, add internal default timings to
the connector driver, because the connector driver should not depend on
VENC, and it can be used with any other analog TV encoder.

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