usb: correct trivial typo in drivers/usb/host/Kconfig

Correct "Enbale" -> "Enable", in the desc for USB_HCD_BCMA
and USB_HCD_SSB.

Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>