drm/i915/adl_p: Don't config MBUS and DBUF during display initialization

Alderlake-P don't have programing sequences for MBUS or DBUF during
display initializaiton, instead it requires programing to those
registers during modeset because it to depend on the pipes left
enabled.

Bspec: 49213
Cc: Matt Roper <matthew.d.roper@intel.com>
Signed-off-by: José Roberto de Souza <jose.souza@intel.com>
Signed-off-by: Clinton Taylor <Clinton.A.Taylor@intel.com>
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Reviewed-by: Stanislav Lisovskiy <stanislav.lisovskiy@intel.com>
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210519000625.3184321-7-lucas.demarchi@intel.com

drivers/gpu/drm/i915/display/intel_display_power.c

@@ -5245,6 +5245,9 @@ static void gen12_dbuf_slices_config(struct drm_i915_private *dev_priv)
 {
 	enum dbuf_slice slice;
 
+	if (IS_ALDERLAKE_P(dev_priv))
+		return;
+
 	for_each_dbuf_slice(dev_priv, slice)
 		intel_de_rmw(dev_priv, DBUF_CTL_S(slice),
 			     DBUF_TRACKER_STATE_SERVICE_MASK,
@@ -5256,6 +5259,9 @@ static void icl_mbus_init(struct drm_i915_private *dev_priv)
 	unsigned long abox_regs = INTEL_INFO(dev_priv)->abox_mask;
 	u32 mask, val, i;
 
+	if (IS_ALDERLAKE_P(dev_priv))
+		return;
+
 	mask = MBUS_ABOX_BT_CREDIT_POOL1_MASK |
 		MBUS_ABOX_BT_CREDIT_POOL2_MASK |
 		MBUS_ABOX_B_CREDIT_MASK |