ARM: dts: msm: Add support for QoS configuration elements for MSM8996

Add the QoS configuration elements in device tree so that they
can be configured easily for each edge or target.

Change-Id: If647724a489cf5e3968bbbba00c3619efaa74f12
Signed-off-by: Atish Kumar Patra <apatra@codeaurora.org>