soc: qcom: add CDSP request manager for CPU L3 clock voting

CDSPRM module consists of a rpmsg based driver to receive requests
from CDSP subsystem for CPU L3 clock frequency and QoS
requirements.
L3 frequency requests are forwarded to the devfreq governor.
QoS requests are handled within this driver by using pm qos APIs.
CDSP votes for L3 clock to improve IOcoherent bandwidth for better
performance and votes for QoS latency to reduce FastRPC overhead.

Change-Id: Ib6acb3f25e535592ea63388a019fca3c44342190
Acked-by: Sreekanth Gande <sgande@qti.qualcomm.com>
Signed-off-by: Tharun Kumar Merugu <mtharu@codeaurora.org>