Bluetooth: btintel: Fix the LED is not turning off immediately

Some platforms have an issue with BT LED when the interface is
down or BT radio is turned off, which takes 5 seconds to BT LED
goes off. This command turns off the BT LED immediately.

This patch sends the Intel vendor command to turn off the LED.

Signed-off-by: Tedd Ho-Jeong An <tedd.an@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>