tests/boards/intel_adsp/smoke: Add board hardware features smoke test

These are descended from a private collection of test rigs I've been
semi-curating.  Getting cache, clock and memory space setup consistent
is mildly complicated on these devices and we've had bugs in all these
areas.

+ Check cache/uncache memory space setup, and make sure that the
  incoherent cache is operating as expected.

+ Make sure all cores agree with clocking setup.

+ Quickly benchmark a two-instruction loop to detect messups with
  instruction caching.

Signed-off-by: Andy Ross <andrew.j.ross@intel.com>