omapdss: features: fix supported outputs for OMAP4

omapdss: features: fix supported outputs for OMAP4

The support outputs struct for overlay managers is incorrect for OMAP4. Make
these changes:

- DPI isn't supported via the LCD1 overlay manager, remove DPI as a supported
  output.
- the TV manager can suppport DPI, but the omapdss driver doesn't support that
  yet, we require some muxing at the DSS level, and we also need to configure
  the hdmi pll in the DPI driver so that the TV manager has a pixel clock. We
  don't support that yet.

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