drm/panel-simple: fix the warnings for the Evervision VGG644804

The panel lacked the connector type which causes a warning. Adding the
connector type reveals wrong bus_flags and bits per pixel. Fix all of
it.

Fixes: 1319f217 ("drm/panel-simple: add Evervision VGG644804 panel entry")
Signed-off-by: Michael Walle <mwalle@kernel.org>
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://lore.kernel.org/r/20250520074110.655114-1-mwalle@kernel.org