dts: nxp: Disable kw40/41 gpiob interrupts

Ports B and C share a common interrupt vector on kw40 and kw41z socs,
but we don't currently have a way to express this in device tree. A
check was added in commit 77cb942a that
correctly causes build errors on kw40/41 boards when both ports are
enabled.

Disable the port b interrupt for now until we have a better way to
handle this.

Signed-off-by: Maureen Helm <maureen.helm@nxp.com>