Fix CMake variable name

Signed-off-by: Ronald Cron <[email protected]>

Author: ronald-cron-arm

programs/psa/CMakeLists.txt

@@ -11,7 +11,7 @@ if(GEN_FILES)
         OUTPUT
             ${CMAKE_CURRENT_BINARY_DIR}/psa_constant_names_generated.c
         COMMAND
-            ${MBEDTLS_PYTHON_EXECUTABLE}
+            ${PSA_CRYPTO_PYTHON_EXECUTABLE}
                 ${CMAKE_CURRENT_SOURCE_DIR}/../../scripts/generate_psa_constants.py
                 ${CMAKE_CURRENT_BINARY_DIR}
         WORKING_DIRECTORY