Revert "drm/i915/dgfx: DGFX uses direct VBT pin mapping"

Revert "drm/i915/dgfx: DGFX uses direct VBT pin mapping"

This reverts commit 562f33836f519a235e5c5e71bcc723ab1faccd2f.
For BMG it seems that the VBT to DDI mapping does not follow DG1, and
DG2, but follows ADLP mapping given in Bspec:20124.

Signed-off-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
Signed-off-by: Balasubramani Vivekanandan <balasubramani.vivekanandan@intel.com>
Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
Signed-off-by: Radhakrishna Sripada <radhakrishna.sripada@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240430172850.1881525-15-radhakrishna.sripada@intel.com