mk: add new test-basic rule

mk: add new test-basic rule

Since "make test" and "make test-build" does dependency resolving, they
check for all dependent components (lib and drivers) which takes a few
seconds.

This is a good feature during development, but if the target is only
running unit test, that step is unnecessary, it is possible to compile
once and run unit test multiple times, without checking any code update.

For this purpose, a new make rule "make test-basic" added. Which only
runs the unit test, expects that unit test already compiled.

Signed-off-by: Ferruh Yigit <ferruh.yigit@intel.com>
Acked-by: Bruce Richardson <bruce.richardson@intel.com>