staging: media: ipu3: remove ftrace-like logging

This patch fixes the following checkpatch.pl warnings in ipu3.c:

WARNING: Unnecessary ftrace-like logging - prefer using ftrace
+       dev_dbg(dev, "enter %s\n", __func__);

WARNING: Unnecessary ftrace-like logging - prefer using ftrace
+       dev_dbg(dev, "leave %s\n", __func__);

WARNING: Unnecessary ftrace-like logging - prefer using ftrace
+       dev_dbg(dev, "enter %s\n", __func__);

WARNING: Unnecessary ftrace-like logging - prefer using ftrace
+       dev_dbg(dev, "leave %s\n", __func__);

Fixes: 7fc7af64 ("media: staging/intel-ipu3: Add imgu top level pci device driver")
Signed-off-by: Ricardo B. Marliere <ricardo@marliere.net>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>