cpufreq: qcom-nvmem: also accept operating-points-v2-krait-cpu

the qcom-cpufreq-nvmem driver attempts to support both Qualcomm Kryo
(newer 64-bit ARMv8 cores) and Krait (older 32-bit ARMv7 cores). It
makes no sense to use 'operating-points-v2-kryo-cpu' compatibility node
for the Krait cores. Add support for 'operating-points-v2-krait-cpu'
compatibility string.

Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>