USB: ehci/mxc: compile fix

Commit
	65fd4272 (USB: ehci tdi : let's tdi_reset set host mode)

broke the build using ARM's mx51_defconfig:

 	  CC      drivers/usb/host/ehci-hcd.o
 	In file included from drivers/usb/host/ehci-hcd.c:1166:
 	drivers/usb/host/ehci-mxc.c: In function 'ehci_mxc_drv_probe':
 	drivers/usb/host/ehci-mxc.c:192: error: 'ehci' undeclared (first use in this function)
 	drivers/usb/host/ehci-mxc.c:192: error: (Each undeclared identifier is reported only once
 	drivers/usb/host/ehci-mxc.c:192: error: for each function it appears in.)
 	drivers/usb/host/ehci-mxc.c:117: warning: unused variable 'temp'
 	make[3]: *** [drivers/usb/host/ehci-hcd.o] Error 1
 	make[2]: *** [drivers/usb/host/ehci-hcd.o] Error 2
 	make[1]: *** [sub-make] Error 2
 	make: *** [all] Error 2

Fix it together with the warning about the unused variable and use
msleep instead of mdelay as requested by Alan Stern.

Cc: Dinh Nguyen <Dinh.Nguyen@freescale.com>
Cc: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Tested-by: Nguyen Dinh-R00091 <R00091@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>