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>

drivers/usb/dwc2/debug.h

@@ -0,0 +1,27 @@
+/**
+ * debug.h - Designware USB2 DRD controller debug header
+ *
+ * Copyright (C) 2015 Intel Corporation
+ * Mian Yousaf Kaukab <yousaf.kaukab@intel.com>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2  of
+ * the License as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include "core.h"
+
+#ifdef CONFIG_DEBUG_FS
+extern int dwc2_debugfs_init(struct dwc2_hsotg *);
+extern void dwc2_debugfs_exit(struct dwc2_hsotg *);
+#else
+static inline int dwc2_debugfs_init(struct dwc2_hsotg *hsotg)
+{  return 0;  }
+static inline void dwc2_debugfs_exit(struct dwc2_hsotg *hsotg)
+{  }
+#endif