drm/msm/dp: Add missing drm_device backpointer

'6cba3fe43341 ("drm/dp: Add backpointer to drm_device in drm_dp_aux")'
introduced a mandator drm_device backpointer in struct drm_dp_aux, but
missed the msm DP driver. Fix this.

Fixes: 6cba3fe ("drm/dp: Add backpointer to drm_device in drm_dp_aux")
Link: https://lore.kernel.org/linux-arm-msm/20210625034721.1287948-1-bjorn.andersson@linaro.org/
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

drivers/gpu/drm/msm/dp/dp_aux.c

@@ -441,7 +441,7 @@ void dp_aux_deinit(struct drm_dp_aux *dp_aux)
 	dp_catalog_aux_enable(aux->catalog, false);
 }
 
-int dp_aux_register(struct drm_dp_aux *dp_aux)
+int dp_aux_register(struct drm_dp_aux *dp_aux, struct drm_device *drm_dev)
 {
 	struct dp_aux_private *aux;
 	int ret;
@@ -455,6 +455,7 @@ int dp_aux_register(struct drm_dp_aux *dp_aux)
 
 	aux->dp_aux.name = "dpu_dp_aux";
 	aux->dp_aux.dev = aux->dev;
+	aux->dp_aux.drm_dev = drm_dev;
 	aux->dp_aux.transfer = dp_aux_transfer;
 	ret = drm_dp_aux_register(&aux->dp_aux);
 	if (ret) {

drivers/gpu/drm/msm/dp/dp_aux.h

@@ -9,7 +9,7 @@
 #include "dp_catalog.h"
 #include <drm/drm_dp_helper.h>
 
-int dp_aux_register(struct drm_dp_aux *dp_aux);
+int dp_aux_register(struct drm_dp_aux *dp_aux, struct drm_device *drm_dev);
 void dp_aux_unregister(struct drm_dp_aux *dp_aux);
 void dp_aux_isr(struct drm_dp_aux *dp_aux);
 void dp_aux_init(struct drm_dp_aux *dp_aux);

drivers/gpu/drm/msm/dp/dp_display.c

@@ -253,7 +253,7 @@ static int dp_display_bind(struct device *dev, struct device *master,
 	}
 
 	dp->aux->drm_dev = drm;
-	rc = dp_aux_register(dp->aux);
+	rc = dp_aux_register(dp->aux, drm);
 	if (rc) {
 		DRM_ERROR("DRM DP AUX register failed\n");
 		goto end;