Implement support for MBEDTLS_PSA_CRYPTO_BUILTIN_KEYS

According to the design in psa-driver-interface.md. Compiles without
issue in test_psa_crypto_drivers.

Signed-off-by: Steven Cooreman <steven.cooreman@silabs.com>
diff --git a/tests/scripts/all.sh b/tests/scripts/all.sh
index f768e1e..a85c7ce 100755
--- a/tests/scripts/all.sh
+++ b/tests/scripts/all.sh
@@ -2267,6 +2267,7 @@
     msg "build: MBEDTLS_PSA_CRYPTO_DRIVERS w/ driver hooks"
     scripts/config.py full
     scripts/config.py set MBEDTLS_PSA_CRYPTO_DRIVERS
+    scripts/config.py set MBEDTLS_PSA_CRYPTO_BUILTIN_KEYS
     # Need to define the correct symbol and include the test driver header path in order to build with the test driver
     loc_cflags="$ASAN_CFLAGS -DPSA_CRYPTO_DRIVER_TEST"
     loc_cflags="${loc_cflags} -DMBEDTLS_PSA_ACCEL_KEY_TYPE_AES"