drm/i915/icl: Add power well support

drm/i915/icl: Add power well support

Add the definition for ICL power wells and their mapping to power
domains. On ICL there are 3 power well control registers, we'll select
the correct one based on higher bits of the power well ID. The offset
for the control and status flags within this register is based on the
lower bits of the ID as on older platforms.

As the DC state programming is also the same as on old platforms we can
reuse the corresponding helpers. For this we mark here the DC-off power
well as shared among multiple platforms.

Other than the above the delta between old platforms and ICL:
- Pipe C has its own power well, so we can save some additional power in the
  pipe A+B and (non-eDP) pipe A configurations.
- Power wells for port E/F DDI/AUX IO and Thunderbolt 1-4 AUX IO

v2:
- Rebase on drm-tip after prep patch for this was merged there as
  requested by Paulo.
- Actually add the new AUX and DDI power well control regs (Rakshmi)

v3:
- Fix power well register names in code comments
- Add TBT AUX->power well 3 dependency

v4:
- Rebase

v5:
- Detach AUX power wells from the INIT power domain. These power wells
  can only be enabled in a TC/TBT connected state and otherwise not
  needed during driver initialization.

v6:
- Use _MMIO_PORT(...) instead _MMIO(_PICK(...)) (Paulo)
  Fix checkpatch warnings.

Cc: Animesh Manna <animesh.manna@intel.com>
Cc: Rakshmi Bhatia <rakshmi.bhatia@intel.com>
Cc: Paulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Animesh Manna <animesh.manna@intel.com> (v1)
Reviewed-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180626142232.22361-1-imre.deak@intel.com