drm/i915: Assorted dev_priv cleanups

A small selection of macros which can only accept dev_priv from
now on and a resulting trickle of fixups.

Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: David Weinehall <david.weinehall@linux.intel.com>
diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index 117a714..581971f 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -942,14 +942,14 @@ intel_dp_aux_ch(struct intel_dp *intel_dp,
 		uint8_t *recv, int recv_size)
 {
 	struct intel_digital_port *intel_dig_port = dp_to_dig_port(intel_dp);
-	struct drm_device *dev = intel_dig_port->base.base.dev;
-	struct drm_i915_private *dev_priv = to_i915(dev);
+	struct drm_i915_private *dev_priv =
+			to_i915(intel_dig_port->base.base.dev);
 	i915_reg_t ch_ctl = intel_dp->aux_ch_ctl_reg;
 	uint32_t aux_clock_divider;
 	int i, ret, recv_bytes;
 	uint32_t status;
 	int try, clock = 0;
-	bool has_aux_irq = HAS_AUX_IRQ(dev);
+	bool has_aux_irq = HAS_AUX_IRQ(dev_priv);
 	bool vdd;
 
 	pps_lock(intel_dp);