Adds Corstone 315 to per-patch tests

Change-Id: Ic3027c94f57e50631d3a63472eb1446b562c990a
Signed-off-by: Matthew Dalzell <matthew.dalzell@arm.com>
diff --git a/build_helper/build_helper_configs.py b/build_helper/build_helper_configs.py
index db99ef8..390531e 100755
--- a/build_helper/build_helper_configs.py
+++ b/build_helper/build_helper_configs.py
@@ -331,6 +331,9 @@
                     # corstone1000_GCC_2_RegS_Debug_BL2_NSOFF_CS1K_TEST_FVP
                     ("arm/corstone1000", "GCC_10_3", "2",
                      "RegS", "OFF", "Debug", True, "", "NSOFF, CS1K_TEST, FVP"),
+                    # corstone315_ARMCLANG_1_RegBL2_RegS_RegNS_Debug_BL2
+                    ("arm/mps4/corstone315", "ARMCLANG_6_21", "1",
+                     "RegBL2, RegS, RegNS", "OFF", "Debug", True, "", ""),
                     # MUSCA_B1_GCC_1_RegBL2_RegS_RegNS_Minsizerel_BL2
                     ("arm/musca_b1", "GCC_10_3", "1",
                      "RegBL2, RegS, RegNS", "OFF", "Minsizerel", True, "", ""),