The irq_of_parse_and_map will return 0 as a invalid irq.

Set irq_bt to -1 in this case, so that the btmrvl resume/suspend code
would not try to enable/disable it.
Signed-off-by: NJeffy Chen <jeffy.chen@rock-chips.com>
Reviewed-by: NBrian Norris <briannorris@chromium.org>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>