test_tickless: improve testcase.ini filter

The filter specification now matches the code. We can run on any x86,
or those ARM boards where the test's timestamp.c has _Timestamp*
implementations.

Change-Id: Ib81e5379f892beb3783dd3c345cd536c883a74de
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>