audio policy: fix attached devices validation

Consider all supported devices in an io profile and
not only the first one when looking for a match with attached
devices.
Failing to do so would cause the device validation to fail
if supported devices are not declared in a specific order
in the io profile descriptor in audio_policy.conf

Bug: 17532764.
Change-Id: Id27c9192e21de7f075076e17eb8c48e7e42847f6