soc: qcom: socinfo: Fix array out-of-bounds access

Socinfo driver's socinfo_get_id_string() does an array based
indexing with the socid to get the entry for the current
platform in soc_id[]. However, the soc_id[] is linearly
mapped and not arranged to be indexed with the socid (unlike
previous targets). This would cause an out-of-bounds array
access in the soc_id[] array.

Hence to fetch the name, rely on the already existing function,
socinfo_machine(), which would iterate over the array and
return a matching machine name for the id supplied.

Change-Id: Ib7070732ac4ec99a32eb3f79c74abf2903398f53
Signed-off-by: Raghavendra Rao Ananta <rananta@codeaurora.org>