Build: Configuration for Regression IPC test

- Disable Regression in ConfigCoreIPC.cmake and
  ConfigCoreIPCTfmLevel2.cmake.
- Add new build configuration to run regresstion with IPC model and IPC
  model isolation level 2.
- Add explicit setting for basic project build variables in all build
  configurations

Change-Id: I9a627ca08209a5b8e295c3cac9538d6e80f2e669
Signed-off-by: Edison Ai <edison.ai@arm.com>
diff --git a/ConfigCoreIPCTfmLevel2.cmake b/ConfigCoreIPCTfmLevel2.cmake
index dac3d5e..9525ecd 100644
--- a/ConfigCoreIPCTfmLevel2.cmake
+++ b/ConfigCoreIPCTfmLevel2.cmake
@@ -26,9 +26,10 @@
 ##These variables select how the projects are built. Each project will set
 #various project specific settings (e.g. what files to build, macro
 #definitions) based on these.
-set (REGRESSION True)
+set (REGRESSION False)
 set (CORE_TEST False)
 set (CORE_IPC True)
+set (PSA_API_TEST False)
 
 # TF-M isolation level: 1..3
 set (TFM_LVL 2)