sunxi: video: Drop disabling of backend / lcdc / hdmi encoder on modeset

The enable flags are initialized to 0 already by engines_init, so now that
we no longer retry the mode-set, the disabling of the blocks in
sunxi_mode_set() is a no-op.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
sunxi: video: Improve monitor video-mode option handling

Add a sunxi_monitor enum and parse the monitor option string into this enum
once, rather then doing strcmp-s on it in various places. This also adds
checking for it being a valid value.

This also adds new "auto" and "lcd" values in preparation for lcd support.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
sunxi: video: Prepare for lcd support

Move various display init bits which are hdmi/dvi specific under
if (monitor == dvi || monitor == hdmi) conditionals as preperation for adding
lcd support.

Also rename sunxi_lcdc_mode_set to sunxi_lcdc_tcon1_mode_set, as it sets the
timings for tcon1, and for lcd support we need a similar function operating
on tcon0.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
sunxi: video: Modify sunxi_lcdc_pll_set to work with both tcon0 and tcon1

Modify sunxi_lcdc_pll_set to work with both tcon0 and tcon1, this is a
preparation patch for adding lcd support.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
sunxi: video: Add lcd output support

WIP

Signed-off-by: Hans de Goede <hdegoede@redhat.com>