soc: qcom: hyp_core_ctl: Add frequency QoS support

While isolating/un-isolating CPUs to cater the needs of other
virtual machines in the system, clients would want to run CPUs
at some reasonable frequency to balance perf/power needs.
This patch adds frequency QoS support to enable clients to run
the CPUs at desired frequecy.

Change-Id: I3c577815ddc246df2ff1d87218db18c2bfb05819
Signed-off-by: Satya Durga Srinivasu Prabhala <satyap@codeaurora.org>