Add unit tests for hipMemGetDefaultMemPool API

This change adds 2 new tests:
- Unit_hipMemGetDefaultMemPool_Negative
- Unit_hipMemGetDefaultMemPool_Basic

Signed-off-by: Sebastian Luzynski <sebastian.luzynski@amd.com>

Author: sluzynsk-amd

projects/hip-tests/catch/unit/memory/CMakeLists.txt

@@ -211,7 +211,8 @@ set(TEST_SRC
     hipFreeMipmappedArray.cc
     hipHostAlloc.cc
     hipMemSetMemPool.cc
-    hipMemGetMemPool.cc)
+    hipMemGetMemPool.cc
+    hipMemGetDefaultMemPool.cc)
 
 if(HIP_PLATFORM MATCHES "amd")
   set(TEST_SRC