drm/i915: Nuke intel_digital_port->port

Remove intel_digital_port->port and replace its users with
intel_encoder->port. intel_encoder->port is a superset of
intel_digital_port->port, and it works correctly even for
MST encoders.

v2: Eliminate a few dp_to_dig_port()->base.port cases too (DK)

Performed with cocci:
@@
@@
struct intel_digital_port {
       ...
-       enum port port;
       ...
}

@@
struct intel_digital_port *D;
expression E;
@@
- D->port = E;

@@
struct intel_digital_port *D;
@@
- D->port
+ D->base.port

@
expression E;
@@
(
- dp_to_dig_port(E)->port
+ dp_to_dig_port(E)->base.port
|
- enc_to_dig_port(E)->port
+ to_intel_encoder(E)->port
)

@@
expression E;
@@
- to_intel_encoder(&E->base)
+ E

@@
struct intel_digital_port *D;
identifier I, M;
@@
  I = &D->base
<...
(
- D->base.M
+ I->M
|
- &D->base
+ I
)
...>

@@
identifier D;
expression E;
identifier M;
@@
 D = enc_to_dig_port(&E->base)
<...
(
- D->base.M
+ E->M
|
- &D->base
+ E
)
...>

@@
identifier D, DP;
expression E;
identifier M;
@@
 DP = enc_to_intel_dp(&E->base)
<...
(
- dp_to_dig_port(DP)->base.M
+ E->M
|
- &dp_to_dig_port(DP)->base
+ E
)
...>

@@
expression E;
identifier M;
@@
(
- enc_to_dig_port(&E->base)->base.M
+ E->M
|
- enc_to_dig_port(&E->base)->base
+ E
|
- enc_to_mst(&E->base)->primary->base.port
+ E->port
)

@@
expression E;
identifier D;
@@
- struct intel_digital_port *D = E;
... when != D

Cc: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>
Reviewed-by: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>
Acked-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171109152434.32074-1-ville.syrjala@linux.intel.com
diff --git a/drivers/gpu/drm/i915/intel_dpio_phy.c b/drivers/gpu/drm/i915/intel_dpio_phy.c
index 5958d3d..76473e9 100644
--- a/drivers/gpu/drm/i915/intel_dpio_phy.c
+++ b/drivers/gpu/drm/i915/intel_dpio_phy.c
@@ -586,9 +586,8 @@ bxt_ddi_phy_calc_lane_lat_optim_mask(uint8_t lane_count)
 void bxt_ddi_phy_set_lane_optim_mask(struct intel_encoder *encoder,
 				     uint8_t lane_lat_optim_mask)
 {
-	struct intel_digital_port *dport = enc_to_dig_port(&encoder->base);
-	struct drm_i915_private *dev_priv = to_i915(dport->base.base.dev);
-	enum port port = dport->port;
+	struct drm_i915_private *dev_priv = to_i915(encoder->base.dev);
+	enum port port = encoder->port;
 	enum dpio_phy phy;
 	enum dpio_channel ch;
 	int lane;
@@ -613,9 +612,8 @@ void bxt_ddi_phy_set_lane_optim_mask(struct intel_encoder *encoder,
 uint8_t
 bxt_ddi_phy_get_lane_lat_optim_mask(struct intel_encoder *encoder)
 {
-	struct intel_digital_port *dport = enc_to_dig_port(&encoder->base);
-	struct drm_i915_private *dev_priv = to_i915(dport->base.base.dev);
-	enum port port = dport->port;
+	struct drm_i915_private *dev_priv = to_i915(encoder->base.dev);
+	enum port port = encoder->port;
 	enum dpio_phy phy;
 	enum dpio_channel ch;
 	int lane;
@@ -641,7 +639,7 @@ void chv_set_phy_signal_level(struct intel_encoder *encoder,
 {
 	struct drm_i915_private *dev_priv = to_i915(encoder->base.dev);
 	struct intel_digital_port *dport = enc_to_dig_port(&encoder->base);
-	struct intel_crtc *intel_crtc = to_intel_crtc(dport->base.base.crtc);
+	struct intel_crtc *intel_crtc = to_intel_crtc(encoder->base.crtc);
 	enum dpio_channel ch = vlv_dport_to_channel(dport);
 	enum pipe pipe = intel_crtc->pipe;
 	u32 val;