drm/i915/dvo: Actually initialize the DVO encoder type

We call drm_encoder_init() before determining the correct
encoder type, thus we always end up with DRM_MODE_ENCODER_NONE.
Determine the correct encoder type earlier.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20221118105525.27254-4-ville.syrjala@linux.intel.com


Reviewed-by: Jani Nikula <jani.nikula@intel.com>