a2dp: Invalidate cache if SetConfiguration fails

a2dp: Invalidate cache if SetConfiguration fails

If SetConfiguration fails with Unsupported Configuration it might
indicate that either the capabilities stored are incorrect or the seid
may have changed, so this attempt to invalidate the remote seps loaded
from cache when that happens so the next time there is an attempt to
discover this will force Get(All)Capabilities to be called and cause
the cache to be updated.

Fixes https://github.com/bluez/bluez/issues/178

Signed-off-by: Anuj Jain <anuj01.jain@samsung.com>
Signed-off-by: Ayush Garg <ayush.garg@samsung.com>