arm/komeda: Compile komeda_debugfs_init() only if CONFIG_DEBUG_FS is enabled

We don't call this function if CONFIG_DEBUG_FS is not defined, but we
should not be compiling it either, as the declaration of the debugfs
core functions is not included.

Reported by the kbuild test robot.
Reviewed-by: James Qian Wang (Arm Technology China) <james.qian.wang@arm.com>
Signed-off-by: Liviu Dudau <liviu.dudau@arm.com>

drivers/gpu/drm/arm/display/komeda/komeda_dev.c

@@ -44,6 +44,7 @@ static const struct file_operations komeda_register_fops = {
 	.release	= single_release,
 };
 
+#ifdef CONFIG_DEBUG_FS
 static void komeda_debugfs_init(struct komeda_dev *mdev)
 {
 	if (!debugfs_initialized())
@@ -56,6 +57,7 @@ static void komeda_debugfs_init(struct komeda_dev *mdev)
 	debugfs_create_file("register", 0444, mdev->debugfs_root,
 			    mdev, &komeda_register_fops);
 }
+#endif
 
 static int komeda_parse_pipe_dt(struct komeda_dev *mdev, struct device_node *np)
 {