drm/i915: Nuke aux regs from intel_dp

Just store function pointers that give us the correct register offsets
instead of storing the register offsets themselves. Slightly less
efficient perhaps but saves a few bytes and better matches how we do
things elsewhere.

v2: Keep a local array of data registers (Chris)

Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180222181036.15251-3-ville.syrjala@linux.intel.com
diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index ad7b6a6..95e2b69 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -960,8 +960,6 @@ struct intel_dp_compliance {
 
 struct intel_dp {
 	i915_reg_t output_reg;
-	i915_reg_t aux_ch_ctl_reg;
-	i915_reg_t aux_ch_data_reg[5];
 	uint32_t DP;
 	int link_rate;
 	uint8_t lane_count;
@@ -1046,6 +1044,9 @@ struct intel_dp {
 				     int send_bytes,
 				     uint32_t aux_clock_divider);
 
+	i915_reg_t (*aux_ch_ctl_reg)(struct intel_dp *dp);
+	i915_reg_t (*aux_ch_data_reg)(struct intel_dp *dp, int index);
+
 	/* This is called before a link training is starterd */
 	void (*prepare_link_retrain)(struct intel_dp *intel_dp);