drm/i915/bios: abstract finding VBT in BIOS to a separate function
drm/i915/bios: abstract finding VBT in BIOS to a separate function

Improve clarity. No functional changes.

Signed-off-by: Jani Nikula <ba783f3beccaedfda693f41a15407d612a629408@intel.com>
Signed-off-by: Daniel Vetter <c1b6782c4af8f0673da8923a0702a1832e5940f4@ffwll.ch>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs