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