Update path in programs/psa/CMakeList.txt

This commit updates the path to the generate_psa_constants.py script in
programs/psa/CMakeList.txt file.

Signed-off-by: Harry Ramsey <harry.ramsey@arm.com>
diff --git a/tf-psa-crypto/programs/psa/CMakeLists.txt b/tf-psa-crypto/programs/psa/CMakeLists.txt
index 625b6e1..2356c81 100644
--- a/tf-psa-crypto/programs/psa/CMakeLists.txt
+++ b/tf-psa-crypto/programs/psa/CMakeLists.txt
@@ -14,10 +14,10 @@
             ${CMAKE_CURRENT_BINARY_DIR}/psa_constant_names_generated.c
         COMMAND
             ${MBEDTLS_PYTHON_EXECUTABLE}
-                ${CMAKE_CURRENT_SOURCE_DIR}/../../../scripts/generate_psa_constants.py
+                ${CMAKE_CURRENT_SOURCE_DIR}/../../scripts/generate_psa_constants.py
                 ${CMAKE_CURRENT_BINARY_DIR}
         WORKING_DIRECTORY
-            ${CMAKE_CURRENT_SOURCE_DIR}/../../..
+            ${CMAKE_CURRENT_SOURCE_DIR}/../..
         DEPENDS
             ${CMAKE_CURRENT_SOURCE_DIR}/../../scripts/generate_psa_constants.py
             ${CMAKE_CURRENT_SOURCE_DIR}/../../include/psa/crypto_values.h