USB: cdc: add control-signal defines

Add defines for the Control Signal Bitmap Values from section 6.2.14
SetControlLineState of the CDC specification version 1.1.

Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20220725075841.1187-2-johan@kernel.org


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>