usb: dwc3: Fix debugfs creation flow

Creation EP's debugfs called earlier than debugfs folder for dwc3
device created. As result EP's debugfs are created in '/sys/kernel/debug'
instead of '/sys/kernel/debug/usb/dwc3.1.auto'.

Moved dwc3_debugfs_init() function call before calling
dwc3_core_init_mode() to allow create dwc3 debugfs parent before
creating EP's debugfs's.

Fixes: 8d396bb0 ("usb: dwc3: debugfs: Add and remove endpoint dirs dynamically")
Cc: stable <stable@vger.kernel.org>
Reviewed-by: Jack Pham <jackp@codeaurora.org>
Signed-off-by: Minas Harutyunyan <Minas.Harutyunyan@synopsys.com>
Link: https://lore.kernel.org/r/01fafb5b2d8335e98e6eadbac61fc796bdf3ec1a.1623948457.git.Minas.Harutyunyan@synopsys.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>