cmake: Add support for Cortex-M23 to build system

Add Cortex-M23 specific CMake file and update CompilerArmClang67
settings file.

Change-Id: Ieaee7a00ea267fb5eb9cdb7574569a30dc35e5cf
Signed-off-by: Mate Toth-Pal <mate.toth-pal@arm.com>
diff --git a/cmake/Common/CompilerArmClang67.cmake b/cmake/Common/CompilerArmClang67.cmake
index 0ee34b2..2bfd1db 100644
--- a/cmake/Common/CompilerArmClang67.cmake
+++ b/cmake/Common/CompilerArmClang67.cmake
@@ -1,5 +1,5 @@
 #-------------------------------------------------------------------------------
-# Copyright (c) 2017, Arm Limited. All rights reserved.
+# Copyright (c) 2017-2018, Arm Limited. All rights reserved.
 #
 # SPDX-License-Identifier: BSD-3-Clause
 #
@@ -54,6 +54,11 @@
 		set (CMAKE_CXX_FLAGS_CPU "--target=arm-arm-none-eabi -mcpu=cortex-m33")
 		set (CMAKE_ASM_FLAGS_CPU "--cpu=Cortex-M33")
 		set (CMAKE_LINK_FLAGS_CPU "--cpu=Cortex-M33")
+	elseif(${ARM_CPU_TYPE} STREQUAL "Cortex-M23")
+		set (CMAKE_C_FLAGS_CPU "--target=arm-arm-none-eabi -mcpu=cortex-m23")
+		set (CMAKE_CXX_FLAGS_CPU "--target=arm-arm-none-eabi -mcpu=cortex-m23")
+		set (CMAKE_ASM_FLAGS_CPU "--cpu=Cortex-M23")
+		set (CMAKE_LINK_FLAGS_CPU "--cpu=Cortex-M23")
 	else()
 		message(FATAL_ERROR "Unknown ARM cpu setting.")
 	endif()
diff --git a/cmake/Common/CpuM23.cmake b/cmake/Common/CpuM23.cmake
new file mode 100644
index 0000000..19e640b
--- /dev/null
+++ b/cmake/Common/CpuM23.cmake
@@ -0,0 +1,11 @@
+#-------------------------------------------------------------------------------
+# Copyright (c) 2018, Arm Limited. All rights reserved.
+#
+# SPDX-License-Identifier: BSD-3-Clause
+#
+#-------------------------------------------------------------------------------
+
+#This file gatrhers Cortex-M23 specific settings which control the build system.
+set(ARM_CPU_ARHITECTURE "ARM8-M-BASE")
+
+set(ARM_CPU_TYPE "Cortex-M23")