n7100: audio: properly set routing and standby after voice call

Disabling the voice call route using voicecall_default_disable is not
sufficient since there are additional routes which are used during a
voice call, which have to be properly disabled. Also, set the input
device to standy which prevents the mic from not working for the
first time after a voice call.

This could also serve a potential fix for battery drain issues after
voice call.

Original Change-Id in i9300 tree: I0acd41deafd49da50857d6fe6396c3b5270d911c

Change-Id: Id2a0e4f22baca54b0ae7cf775aff6cf5c5b0bd14