drm/i915: Merge the PPS register definitions

The PPS registers are pretty much the same everywhere, the differences
being:
- Register fields appearing, disappearing from one platform to the
  next: panel-reset-on-powerdown, backlight-on, panel-port,
  register-unlock
- Different register base addresses
- Different number of PPS instances: 2 on VLV/CHV/BXT, 1 everywhere
  else.

We can merge the separate set of PPS definitions by extending the PPS
instance argument to all platforms and using instance 0 on platforms
with a single instance. This means we'll need to calculate the register
addresses dynamically based on the given platform and PPS instance.

v2:
- Simplify if ladder in intel_pps_get_registers(). (Ville)

Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1470827254-21954-1-git-send-email-imre.deak@intel.com
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 2cb91ff..0ffab29 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -1749,6 +1749,8 @@
 
 	uint32_t psr_mmio_base;
 
+	uint32_t pps_mmio_base;
+
 	wait_queue_head_t gmbus_wait_queue;
 
 	struct pci_dev *bridge_dev;