drm/amd/display: Add DPIA Link Encoder Assignment Fix for DCN35

For DPIA we should have preferred DIG assignment based on DPIA selected
as per the ASIC design
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Reviewed-by: George Shen <george.shen@amd.com>
Acked-by: Qingqing Zhuo <qingqing.zhuo@amd.com>
Signed-off-by: Mustapha Ghaddar <mghaddar@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/dc/dcn35/dcn35_resource.c

@@ -863,6 +863,28 @@ static const struct dce_i2c_mask i2c_masks = {
 		I2C_COMMON_MASK_SH_LIST_DCN35(_MASK)
 };
 
+/* ========================================================== */
+
+/*
+ * DPIA index | Preferred Encoder     |    Host Router
+ *   0        |      C                |       0
+ *   1        |      First Available  |       0
+ *   2        |      D                |       1
+ *   3        |      First Available  |       1
+ */
+/* ========================================================== */
+static const enum engine_id dpia_to_preferred_enc_id_table[] = {
+		ENGINE_ID_DIGC,
+		ENGINE_ID_DIGC,
+		ENGINE_ID_DIGD,
+		ENGINE_ID_DIGD
+};
+
+static enum engine_id dcn35_get_preferred_eng_id_dpia(unsigned int dpia_index)
+{
+	return dpia_to_preferred_enc_id_table[dpia_index];
+}
+
 static struct dce_i2c_hw *dcn31_i2c_hw_create(
 	struct dc_context *ctx,
 	uint32_t inst)
@@ -1701,6 +1723,7 @@ static struct resource_funcs dcn35_res_pool_funcs = {
 	.update_bw_bounding_box = dcn35_update_bw_bounding_box_fpu,
 	.patch_unknown_plane_state = dcn20_patch_unknown_plane_state,
 	.get_panel_config_defaults = dcn35_get_panel_config_defaults,
+	.get_preferred_eng_id_dpia = dcn35_get_preferred_eng_id_dpia,
 };
 
 static bool dcn35_resource_construct(