btmrvl: set irq_bt to -1 when failed to parse it

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: Jeffy Chen <jeffy.chen@rock-chips.com>
Reviewed-by: Brian Norris <briannorris@chromium.org>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>