drm/i915/dvo: Fixup commentary

Remove the kerneldoc markup applied to non-kerneldoc comments and
convert the multiline comments to the canonical style.

drivers/gpu/drm/i915/intel_dvo.c:303: warning: Function parameter or member 'connector' not described in 'intel_dvo_detect'
drivers/gpu/drm/i915/intel_dvo.c:303: warning: Function parameter or member 'force' not described in 'intel_dvo_detect'
drivers/gpu/drm/i915/intel_dvo.c:382: warning: Function parameter or member 'encoder' not described in 'intel_dvo_get_current_mode'

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180214092909.27040-3-chris@chris-wilson.co.uk