Bluetooth: hci_bcm4377: Increase boot timeout

BCM4388 takes over 2 seconds to boot, so increase the timeout.

Signed-off-by: Hector Martin <marcan@marcan.st>
Reviewed-by: Sven Peter <sven@svenpeter.dev>
Signed-off-by: Sven Peter <sven@svenpeter.dev>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>