Build: Rename TFM_PLATFORM

Arm platforms are moved into arm folder, so the build command
TFM_PLATFORM should do the corresponding changes.

Signed-off-by: Summer Qin <summer.qin@arm.com>
Change-Id: Iba23e4f71d5c5865f358c2b7ce612ba603eff4e7
diff --git a/run-cppcheck.sh b/run-cppcheck.sh
index 8fb9bf9..8ac060f 100755
--- a/run-cppcheck.sh
+++ b/run-cppcheck.sh
@@ -79,7 +79,7 @@
 mcuboot_repo="$(fix_win_path $(get_full_path ./))/../mcuboot"
 
 #Cmake compile params
-cmake_params="-DCMAKE_EXPORT_COMPILE_COMMANDS=1 -DTFM_PLATFORM=mps2/an521 -DTFM_TOOLCHAIN_FILE=$toolchain_file"
+cmake_params="-DCMAKE_EXPORT_COMPILE_COMMANDS=1 -DTFM_PLATFORM=arm/mps2/an521 -DTFM_TOOLCHAIN_FILE=$toolchain_file"
 cmake_params="$cmake_params -DTFM_TEST_REPO_PATH=$test_repo -DMBEDCRYPTO_PATH=$mbedtls_repo"
 cmake_params="$cmake_params -DPSA_ARCH_TESTS_PATH=$psa_arch_tests_repo -DMCUBOOT_PATH=$mcuboot_repo"