Fixes following build error:

  CC      drivers/usb/gadget/fsl_qe_udc.o
drivers/usb/gadget/fsl_qe_udc.c: In function 'qe_eprx_stall_change':
drivers/usb/gadget/fsl_qe_udc.c:156: error: 'struct usb_ctlr' has no member named 'usb_usep'
drivers/usb/gadget/fsl_qe_udc.c:163: error: 'struct usb_ctlr' has no member named 'usb_usep'
drivers/usb/gadget/fsl_qe_udc.c: In function 'qe_eptx_stall_change':
drivers/usb/gadget/fsl_qe_udc.c:173: error: 'struct usb_ctlr' has no member named 'usb_usep'
drivers/usb/gadget/fsl_qe_udc.c:180: error: 'struct usb_ctlr' has no member named 'usb_usep'
drivers/usb/gadget/fsl_qe_udc.c: In function 'qe_eprx_nack':
drivers/usb/gadget/fsl_qe_udc.c:201: error: 'struct usb_ctlr' has no member named 'usb_usep'
drivers/usb/gadget/fsl_qe_udc.c:201: error: 'struct usb_ctlr' has no member named 'usb_usep'
drivers/usb/gadget/fsl_qe_udc.c: In function 'qe_eprx_normal':
drivers/usb/gadget/fsl_qe_udc.c:218: error: 'struct usb_ctlr' has no member named 'usb_usep'
drivers/usb/gadget/fsl_qe_udc.c:218: error: 'struct usb_ctlr' has no member named 'usb_usep'
drivers/usb/gadget/fsl_qe_udc.c: In function 'qe_ep_reset':
drivers/usb/gadget/fsl_qe_udc.c:325: error: 'struct usb_ctlr' has no member named 'usb_usep'
drivers/usb/gadget/fsl_qe_udc.c:342: error: 'struct usb_ctlr' has no member named 'usb_usep'
drivers/usb/gadget/fsl_qe_udc.c: In function 'qe_ep_register_init':
drivers/usb/gadget/fsl_qe_udc.c:515: error: 'struct usb_ctlr' has no member named 'usb_usep'
drivers/usb/gadget/fsl_qe_udc.c: In function 'ch9getstatus':
drivers/usb/gadget/fsl_qe_udc.c:1981: error: 'struct usb_ctlr' has no member named 'usb_usep'
make[2]: *** [drivers/usb/gadget/fsl_qe_udc.o] Error 1
Signed-off-by: Li Yang <leoli@freescale.com>
Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>