USB: musb: Blackfin code needs NOP_USB_XCEIV too

Otherwise we get the link failure:
drivers/built-in.o: In function 'musb_platform_init':
drivers/usb/musb/blackfin.c:300: undefined reference to 'usb_nop_xceiv_register'
make: *** [.tmp_vmlinux1] Error 1

Signed-off-by: Cliff Cai <cliff.cai@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Anand Gadiyar <gadiyar@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>