soc: qcom: socinfo: add missing soc_id sysfs entry

commit 27a344139c186889d742764d3c2a62b395949cef upstream.

Looks like SoC ID is not exported to sysfs for some reason.
This patch adds it!

This is mostly used by userspace libraries like Snapdragon
Neural Processing Engine (SNPE) SDK for checking supported SoC info.

Fixes: efb448d0 ("soc: qcom: Add socinfo driver")
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20200319121418.5180-1-srinivas.kandagatla@linaro.org


Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>