Start to bring up.

Signed-off-by: cctsao1008 <chiacheng.tsao@gmail.com>
Disable tone alarm.

Signed-off-by: cctsao1008 <chiacheng.tsao@gmail.com>
MSC test passed.

Signed-off-by: cctsao1008 <chiacheng.tsao@gmail.com>
add comments.

Signed-off-by: cctsao1008 <chiacheng.tsao@gmail.com>
Composite device test passed with MSC + VCP but the performance  is very very bad,  So the MSC or VCP can  be used independently to  instead of  use composite device, and that will more efficent than it.