drm/i915/mtl: Add gmbus and gpio support

drm/i915/mtl: Add gmbus and gpio support

Add tables to map the GMBUS pin pairs to GPIO registers and port to DDC.
From spec we have registers GPIO_CTL[1-5] mapped to native display phys and
GPIO_CTL[9-12] are mapped to TC ports.

v2:
 - Drop unused GPIO pins(MattR)

BSpec: 49306

Cc: Matt Roper <matthew.d.roper@intel.com>
Original Author: Brian J Lovin
Signed-off-by: Radhakrishna Sripada <radhakrishna.sripada@intel.com>
Reviewed-by: Balasubramani Vivekanandan <balasubramani.vivekanandan@intel.com>
Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220902060342.151824-6-radhakrishna.sripada@intel.com