i9300: audio: fix input device selection

http://review.cyanogenmod.org/61104 broke input device
selection resulting in single channel audio for recordings.

Change-Id: I58d5a0997b22cfe5489030e698e83d1768161132
i9300: audio: bring back removed microphone fix

http://review.cyanogenmod.org/61104 has reverted http://review.cyanogenmod.org/51085
which has bought back issues with microphone after a voice call. After a voice call,
the microphone is either not working or the recorded audio is very faint and not
audible.

The Input device has to be explicitly set to AUDIO_DEVICE_NONE after a voice call,
since force_all_standby() wouldn't work for a voice call usecase.

More details about the fix is included in the gerrit comments for the actual patch.

Change-Id: I87c63b0ec4390ec3e5703e1de5804c10289ee423
Down DPI in 15dp

Change-Id: I8eddf8e21954774a77defe25176ba8c0977e3000
Enable smart cover option through overlay

Change-Id: Ie420e332a045b22eea9b80f40b22c381864313c1
Enable hardware keys enable/disable through overlay

Change-Id: I3d74949852ad227aadde181d327b3c547f75543b
Revert "Down DPI in 15dp"

This reverts commit 3f8ff581cef64d77afce5d0496afe1947636e495.