Revert "sound control: WCD9320: update speaker gain control for Z1"

This reverts commit 2290a2b25ab23a5979b1b93da6a4a6fd05733ad0.
Revert "sound control 3.x: Initial GPL release for WCD9320 Audio Codec"

This reverts commit 1f9b45708e4950c09bcd4fd9bc1b5bd587fed653.
Revert "Sound Control: WCD9320: expose additional controls"

This reverts commit 4143f45e7194cfdee268d81a86646cdd4f211818.
sound: add sound control to increase headphones, speaker and mic gain.

Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>
sound_control: clean the code

* proper 80-char indentation
* add module_exit
* clean up the store functions using proper and modern kstroul
* use unsigned boost vars since we're not accepting negative
values anymore
* remove that stupid and useless version define
sound: wcd9320: tidy up things a little bit. Only accept signed values from now on. The 'headset gain' will only be used to remove some gain noise, increasing it beyond 1 step above the default doesn't make a difference so rather just have it decrease the gain.

Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>