adbd: Add USB Super Speed (3.0) support

When using FunctionFS, adbd is required to specify USB
descriptors as well for ADB function. If underlying host
and device support USB3.0 then USB communication works
if all interface drivers provide SS descriptors as well.
Since, ADBD currently doesn't pass SS descriptors to the
function_fs driver, it results in USB enumeration failure
in SuperSpeed mode when ADB is enabled in USB composition.

Change-Id: I1ae44feaba0615db3f341b3d622a3d64922dbad8
System/core: Start qrng daemon upon power up

1. Set root permissions to qrng daemon upon powerup
2. Drop all permissions except few, just enough to make ioctl calls

Permission for hardware random device is changed in
this gerrit (part of Point 1(above))

Change-Id: Ibe58b7212ba1ec532de9d461266081f3ac4395e3
Signed-off-by: Hariprasad Dhalinarasimha <hnamgund@codeaurora.org>