cpufreq: qcom-nvmem: Introduce cpufreq for ipq95xx

cpufreq: qcom-nvmem: Introduce cpufreq for ipq95xx

IPQ95xx SoCs have different OPPs available for the CPU based on
the SoC variant. This can be determined from an eFuse register
present in the silicon.

Added support for ipq95xx on nvmem driver which helps to
determine OPPs at runtime based on the eFuse register which
has the CPU frequency limits. opp-supported-hw dt binding
can be used to indicate the available OPPs for each limit.

Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Praveenkumar I <ipkumar@codeaurora.org>
Signed-off-by: Kathiravan T <quic_kathirav@quicinc.com>
Signed-off-by: Varadarajan Narayanan <quic_varada@quicinc.com>
[ Viresh: Fixed subject ]
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>