hal: fix backend check routine for combo device

If there is path change between combo device and general device that
shares backend, previous device should be disabled before the new device
is enabled. Otherwise, by the race conditio, the new device would be
disabled by previous combo device
For example, when the previous device is 'speaker-and-headphone' and the new
devcie is 'voice-headphones', there is possibility that
'voice-headphones' get mute by disabling 'speaker-and-headphone'.

BUG=23916345

Change-Id: I765b3c0b6576f22c4aca290846d58dd1c6dfb8c5