soc: qcom: geni: shield geni_icc_get() for ACPI boot

Currently, GENI devices like i2c-qcom-geni fails to probe in ACPI boot,
if interconnect support is enabled.  That's because interconnect driver
only supports DT right now.  As interconnect is not necessarily required
for basic function of GENI devices, let's shield geni_icc_get() call,
and then all other ICC calls become nop due to NULL icc_path, so that
GENI devices keep working for ACPI boot.

Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Link: https://lore.kernel.org/r/20210114112928.11368-1-shawn.guo@linaro.org
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>