Afrikaans: Added missing translation text

Changed wording and added help text.
Brand van Sitter assisted with the help about text.

Change-Id: I4beb02d595ffdfb8753ef79ffa2716e63aed0c97
Merge branch 'cm-10.1' of git://github.com/CyanogenMod/android_packages_apps_DSPManager into cm-10.1