drm/msm/dpu: Use provided drm_minor to initialize debugfs

Instead of reaching into dev->primary for debugfs_root, use the minor
passed into debugfs_init.

This avoids creating the debug directory under /sys/kernel/debug/ and
instead creates the directory under the correct node in
/sys/kernel/debug/dri/<node>/
Reported-by: Stephen Boyd <swboyd@chromium.org>
Reviewed-by: Abhinav Kumar <abhinavk@codeaurora.org>
Reviewed-by: Rob Clark <robdclark@gmail.com>
Signed-off-by: Sean Paul <seanpaul@chromium.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20190524173231.5040-1-sean@poorly.run

drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c

@@ -231,7 +231,7 @@ void *dpu_debugfs_create_regset32(const char *name, umode_t mode,
 			regset, &dpu_fops_regset32);
 }
 
-static int _dpu_debugfs_init(struct dpu_kms *dpu_kms)
+static int _dpu_debugfs_init(struct dpu_kms *dpu_kms, struct drm_minor *minor)
 {
 	void *p = dpu_hw_util_get_log_mask_ptr();
 	struct dentry *entry;
@@ -239,7 +239,7 @@ static int _dpu_debugfs_init(struct dpu_kms *dpu_kms)
 	if (!p)
 		return -EINVAL;
 
-	entry = debugfs_create_dir("debug", dpu_kms->dev->primary->debugfs_root);
+	entry = debugfs_create_dir("debug", minor->debugfs_root);
 	if (IS_ERR_OR_NULL(entry))
 		return -ENODEV;
 
@@ -581,7 +581,7 @@ static int _dpu_kms_drm_obj_init(struct dpu_kms *dpu_kms)
 #ifdef CONFIG_DEBUG_FS
 static int dpu_kms_debugfs_init(struct msm_kms *kms, struct drm_minor *minor)
 {
-	return _dpu_debugfs_init(to_dpu_kms(kms));
+	return _dpu_debugfs_init(to_dpu_kms(kms), minor);
 }
 #endif