/firmware is in the #include path with makes #include "asm/beep.c" sufficient.
Add a comment to generic beep code and make another express intent better.
Change-Id: I587cd704478b894785927bdfe2e647e28614df62
For now due to current lack of an apps/asm, place the ASM/generic code in the
firmware/asm directory.
Additionally, make generic beep code more generic.
Change-Id: I4a69b6ffcbb97d9e6dfde2209c5a118de19e5638