bluetooth: hci_bcm: Give more time to come out of reset

Some supported devices need more time to come out of reset (eg.
BCM4345C5 in AP6256).

I don't have/found a datasheet, so the value was arrive at
experimentally with the Oprange Pi 3 board. Without increased delay,
I got intermittent failures during probe. This is a Bluetooth 5.0
device, so maybe that's why it takes longer to initialize than the
others.

Signed-off-by: Ondrej Jirman <megous@megous.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>