USB: cypress_m8: fix ring-indicator detection and reporting

Fix ring-indicator (RI) status-bit definition, which was defined as CTS,
effectively preventing RI-changes from being detected while reporting
false RI status.

This bug predates git.

Cc: stable@vger.kernel.org
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>