tfm: Fix zephyr-sdk toolchain variant integration

The psa-arch-tests project changed how third-party toolchains are
integrated. This broke the Zephyr sdk.

This patch aligns with the new mechanism.

https://github.com/ARM-software/psa-arch-tests/pull/276

Signed-off-by: Sebastian Bøe <sebastian.boe@nordicsemi.no>

modules/trusted-firmware-m/CMakeLists.txt

@@ -189,6 +189,8 @@ if (CONFIG_BUILD_WITH_TFM)
     COMMAND ${CMAKE_COMMAND}
       -G${CMAKE_GENERATOR}
       -DTFM_TOOLCHAIN_FILE=${ZEPHYR_TRUSTED_FIRMWARE_M_MODULE_DIR}/${TFM_TOOLCHAIN_FILE}
+      -DPSA_TOOLCHAIN_FILE=${CMAKE_CURRENT_LIST_DIR}/psa/GNUARM.cmake
+      -DTOOLCHAIN=INHERIT
       -DTFM_PLATFORM=${TFM_BOARD}
       -DCROSS_COMPILE=${TFM_TOOLCHAIN_PATH}/${TFM_TOOLCHAIN_PREFIX}
       -DCMAKE_BUILD_TYPE=${TFM_CMAKE_BUILD_TYPE}

modules/trusted-firmware-m/psa/GNUARM.cmake

@@ -0,0 +1,21 @@
+# Copyright (c) 2021 Nordic Semiconductor ASA
+#
+# SPDX-License-Identifier: Apache-2.0
+#
+# This file is the INHERIT equivalent to
+# https://github.com/ARM-software/psa-arch-tests/blob/master/api-tests/tools/cmake/compiler/GNUARM.cmake
+#
+# The INHERIT concept was introduced in
+# https://github.com/ARM-software/psa-arch-tests/pull/276
+
+if(${CPU_ARCH} STREQUAL armv7m)
+  set(TARGET_SWITCH "-march=armv7-m")
+elseif(${CPU_ARCH} STREQUAL armv8m_ml)
+  set(TARGET_SWITCH "-march=armv8-m.main -mcmse")
+elseif(${CPU_ARCH} STREQUAL armv8m_bl)
+  set(TARGET_SWITCH "-march=armv8-m.base -mcmse")
+endif()
+
+set(CMAKE_C_FLAGS   "${TARGET_SWITCH} -g -Wall -Werror -Wextra -fdata-sections -ffunction-sections -mno-unaligned-access")
+set(CMAKE_ASM_FLAGS "${TARGET_SWITCH} -mthumb")
+set(CMAKE_EXE_LINKER_FLAGS "-Xlinker --fatal-warnings -Xlinker --gc-sections -z max-page-size=0x400 -lgcc -lc -lnosys")