dt-bindings: opp: opp-v2-kryo-cpu: support Qualcomm Krait SoCs

Exted the opp-v2-kryo-cpu.yaml to support defining OPP tables for the
previous generation of Qualcomm CPUs, 32-bit Krait-based platforms.

It makes no sense to use 'operating-points-v2-kryo-cpu' compatibility
node for the Krait cores. Add support for the Krait-specific
'operating-points-v2-krait-cpu' compatibility string and the relevant
opp-microvolt subclasses properties.

The listed opp-supported-hw values are applicable only to msm8996 /
msm8996pro platforms. Remove the enum as other platforms will use other
bit values. It makes little sense to list all possible values for all
the platforms here.

Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>