drm/i915/crt: simplify CRT VBT check on pre-VLV/DDI

The VBT int_crt_support can't be trusted on earlier platforms, and is
always set to true in intel_bios.c for pre-DDI and pre-VLV platforms. We
can simplify the output setup by unconditionally calling
intel_crt_init() for these platforms.

Suggested-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190122082307.4003-7-jani.nikula@intel.com