Bluetooth: hci_bcm: respect IRQ polarity from DT

The IRQ polarity is be configured in bcm_setup_sleep(). Make the
configured value match what is in the DeviceTree.

Cc: stable@vger.kernel.org
Fixes: f25a96c8 ("Bluetooth: hci_bcm: enable IRQ capability from devicetree")
Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>