remove redundant call to generate_root_of_trust from its test

platform/FEATURE_EXPERIMENTAL_API/FEATURE_PSA/TARGET_MBED_PSA_SRV/TESTS/its_ps/main.cpp

@@ -36,7 +36,6 @@
 #include "KVStore.h"
 #include "kv_config.h"
 #include "psa_storage_common_impl.h"
-#include "DeviceKey.h"
 
 using namespace utest::v1;
 using namespace mbed;
@@ -219,9 +218,6 @@ utest::v1::status_t case_its_setup_handler(const Case *const source, const size_
         status = psa_ps_reset();
         TEST_ASSERT_EQUAL(PSA_SUCCESS, status);
     }
-#if DEVICEKEY_ENABLED
-    DeviceKey::get_instance().generate_root_of_trust();
-#endif
     return greentea_case_setup_handler(source, index_of_case);
 }