app: Allow overriding PSA_API_TEST_TARGET via Cmake

To allow more flexibility in psa-arch-tests wrt platform naming

Signed-off-by: Øyvind Rønningstad <oyvind.ronningstad@nordicsemi.no>
Change-Id: I281f88fe45e1219a18286f7a7b525ad63f6be6b6
1 file changed