fsl_udc: Don't use create_proc_read_entry()

Don't use create_proc_read_entry() as that is deprecated, but rather use
proc_create_data() and seq_file instead.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Li Yang <leoli@freescale.com>
cc: Felipe Balbi <balbi@ti.com>
cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
cc: linux-usb@vger.kernel.org
cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>