Give a production-sounding name to the p256m option

Now that p256-m is officially a production feature and not just an example,
give it a more suitable name.

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
diff --git a/scripts/config.py b/scripts/config.py
index b7167d1..17fbe65 100755
--- a/scripts/config.py
+++ b/scripts/config.py
@@ -206,7 +206,7 @@
     'MBEDTLS_NO_DEFAULT_ENTROPY_SOURCES', # removes a feature
     'MBEDTLS_NO_PLATFORM_ENTROPY', # removes a feature
     'MBEDTLS_NO_UDBL_DIVISION', # influences anything that uses bignum
-    'MBEDTLS_P256M_EXAMPLE_DRIVER_ENABLED', # influences SECP256R1 KeyGen/ECDH/ECDSA
+    'MBEDTLS_PSA_P256M_DRIVER_ENABLED', # influences SECP256R1 KeyGen/ECDH/ECDSA
     'MBEDTLS_PLATFORM_NO_STD_FUNCTIONS', # removes a feature
     'MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG', # behavior change + build dependency
     'MBEDTLS_PSA_CRYPTO_KEY_ID_ENCODES_OWNER', # incompatible with USE_PSA_CRYPTO