Service: Add a new SLIH test

This patch adds a new SLIH test Partition and new IRQ test suite.
The test logic for SLIH - previously IRQ test - is simplified a lot
as well.

This service is intended to replace the tfm_irq_test_1 service.

Change-Id: Ie319bd57121f73125819bcfbb80943cc557533d9
Signed-off-by: Kevin Peng <kevin.peng@arm.com>
diff --git a/test/CMakeLists.txt b/test/CMakeLists.txt
index 469e4ac..490bbff 100644
--- a/test/CMakeLists.txt
+++ b/test/CMakeLists.txt
@@ -32,6 +32,7 @@
 add_subdirectory(suites/t_cose)
 add_subdirectory(suites/platform)
 add_subdirectory(suites/fwu)
+add_subdirectory(suites/irq)
 
 if(TFM_PSA_API)
     add_subdirectory(suites/ipc)