selftests: ifs: verify IFS ARRAY BIST functionality

There are two selftest scenarios for ARRAY BIST(Board Integrated System
Test) tests:

1. Perform IFS ARRAY BIST tests once on each CPU.
2. Perform IFS ARRAY BIST tests on a random CPU with 3 rounds.

These are not meant to be exhaustive, but are some minimal tests for
for checking IFS ARRAY BIST.

Reviewed-by: Jithu Joseph <jithu.joseph@intel.com>
Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Co-developed-by: Ashok Raj <ashok.raj@intel.com>
Signed-off-by: Ashok Raj <ashok.raj@intel.com>
Signed-off-by: Pengfei Xu <pengfei.xu@intel.com>
Acked-by: Jithu Joseph <jithu.joseph@intel.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>