usb: dwc2: move debugfs code to a separate file

Prepare to add more debug code. Moreover, don't save dentry * for
each file in struct dwc2_hsotg as clean up is done with
debugfs_remove_recursive(). s3c_hsotg_delete_debug() is removed
altogether for the same reason.

Acked-by: John Youn <johnyoun@synopsys.com>
Signed-off-by: Mian Yousaf Kaukab <yousaf.kaukab@intel.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
diff --git a/drivers/usb/dwc2/platform.c b/drivers/usb/dwc2/platform.c
index 185663e..4fb058b 100644
--- a/drivers/usb/dwc2/platform.c
+++ b/drivers/usb/dwc2/platform.c
@@ -47,6 +47,7 @@
 
 #include "core.h"
 #include "hcd.h"
+#include "debug.h"
 
 static const char dwc2_driver_name[] = "dwc2";
 
@@ -121,6 +122,7 @@
 {
 	struct dwc2_hsotg *hsotg = platform_get_drvdata(dev);
 
+	dwc2_debugfs_exit(hsotg);
 	if (hsotg->hcd_enabled)
 		dwc2_hcd_remove(hsotg);
 	if (hsotg->gadget_enabled)
@@ -256,6 +258,8 @@
 
 	platform_set_drvdata(dev, hsotg);
 
+	dwc2_debugfs_init(hsotg);
+
 	return retval;
 }