soc: qcom: rq_stats: add snapshot of run queue stats driver

Add a snapshot of msm_rq_stats driver as of msm-4.4 commit
c605e110ab186049 (Merge "usb: gadget: composite: Return bcdUSB
 0x0310 for Superspeed and higher").

This driver is used to expose statistics to the irq balancer.

Change-Id: I723310d12616f61598b2815e5ed3024418966ecc
Signed-off-by: Kyle Yan <kyan@codeaurora.org>
Signed-off-by: Runmin Wang <runminw@codeaurora.org>