drm/i915/bios: Use drm_dbg_kms() consistently

Replace the few oddball drm_dbg() calls in VBT related code
with drm_dbg_kms() as that is what we generally use for all
display code.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240923152453.11230-2-ville.syrjala@linux.intel.com


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