disp: msm: sde: add pr_fmt for SDE VM layer

Add pr_fmt definition in SDE VM modules for simplifying
searching for DRM driver logs.

Change-Id: I3f83b52dec6479dd89306aed7d84e73928f4e9ef
Signed-off-by: Steve Cohen <cohens@codeaurora.org>

msm/sde/sde_vm_primary.c

@@ -2,6 +2,9 @@
 /*
  * Copyright (c) 2020-2021, The Linux Foundation. All rights reserved.
  */
+
+#define pr_fmt(fmt)	"[drm:%s:%d] " fmt, __func__, __LINE__
+
 #include <linux/notifier.h>
 #include <linux/gunyah/gh_rm_drv.h>
 #include <linux/gunyah/gh_irq_lend.h>