feat(unittests): add a unit test framework.

This patch adds all the infrastructure needed to run unit tests for
RMM, including a new variant for platform host, called `host_test`.

To build and run the tests:

cmake -DRMM_CONFIG=host_defcfg -DHOST_VARIANT=host_test \
  -DCMAKE_BUILD_TYPE=Debug -S ${RMM_SOURCE_DIR} -B ${RMM_BUILD_DIR}
cmake --build ${RMM_BUILD_DIR} -- run-unittests

Signed-off-by: Javier Almansa Sobrino <javier.almansasobrino@arm.com>
Signed-off-by: Soby Mathew <soby.mathew@arm.com>
Change-Id: If16686e111d91c563f8e7281d4ee7ca2864125ae
diff --git a/cmake/CommonConfigs.cmake b/cmake/CommonConfigs.cmake
index 96dc650..6f743ca 100644
--- a/cmake/CommonConfigs.cmake
+++ b/cmake/CommonConfigs.cmake
@@ -51,7 +51,7 @@
 endif()
 
 target_compile_definitions(rmm-common
-    INTERFACE "MAX_CPUS=U(${MAX_CPUS})")
+    INTERFACE "MAX_CPUS=${MAX_CPUS}U")
 
 if(NOT(GRANULE_SIZE EQUAL 4096))
     message(FATAL_ERROR "GRANULE_SIZE is not initialized correctly")