meson: build: Add support for unit tests

Tested: Verified unit test ran successfully:
$ meson -Doe-sdk=enabled -Dtests=enabled build
$ ninja -C build test
ninja: Entering directory `build'
[25/26] Running all tests.
1/1 utest                                   OK       3.00 s

Change-Id: I46acccec5b3c1837ead707e4e4610eb61a023148
Signed-off-by: Adriana Kobylak <anoo@us.ibm.com>
2 files changed