cpufreq: qcom-nvmem: add compatible fallback for ipq806x for no SMEM

cpufreq: qcom-nvmem: add compatible fallback for ipq806x for no SMEM

On some IPQ806x SoC SMEM might be not initialized by SBL. This is the
case for some Google devices (the OnHub family) that can't make use of
SMEM to detect the SoC ID (and socinfo can't be used either as it does
depends on SMEM presence).

To handle these specific case, check if the SMEM is not initialized (by
checking if the qcom_smem_get_soc_id returns -ENODEV) and fallback to
OF machine compatible checking to identify the SoC variant.

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