soc: qcom: rpmhpd: Add RPMh power domain driver

The RPMh power domain driver aggregates the corner votes from various
consumers for the ARC resources and communicates it to RPMh.

With RPMh we use 2 different numbering space for corners, one used
by the clients to express their performance needs, and another used
to communicate to RPMh hardware.

The clients express their performance requirements using a sparse
numbering space which are mapped to meaningful levels like RET, SVS,
NOMINAL, TURBO etc which then get mapped to another number space
between 0 and 15 which is communicated to RPMh. The sparse number space,
also referred to as vlvl is mapped to the continuous number space of 0
to 15, also referred to as hlvl, using command DB.

Some power domain clients could request a performance state only while
the CPU is active, while some others could request for a certain
performance state all the time regardless of the state of the CPU.
We handle this by internally aggregating the votes from both type of
clients and then send the aggregated votes to RPMh.

There are also 3 different types of votes that are comunicated to RPMh
for every resource.
1. ACTIVE_ONLY:
	This specifies the requirement for the resource when the CPU is
 	active
2. SLEEP:
	This specifies the requirement for the resource when the CPU is
	going to sleep
3. WAKE_ONLY:
	This specifies the requirement for the resource when the CPU is
	coming out of sleep to active state

We add data for all power domains on sdm845 SoC as part of the patch.
The driver can be extended to support other SoCs which support RPMh

Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Rajendra Nayak <rnayak@codeaurora.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Andy Gross <andy.gross@linaro.org>