Preserve alphabetical sorting of config options

In the list that is excluded from the full config.

Signed-off-by: David Horstmann <david.horstmann@arm.com>
diff --git a/scripts/config.py b/scripts/config.py
index c7563e4..22bdb5e 100755
--- a/scripts/config.py
+++ b/scripts/config.py
@@ -185,6 +185,7 @@
     'MBEDTLS_NO_UDBL_DIVISION', # influences anything that uses bignum
     'MBEDTLS_PKCS11_C', # build dependency (libpkcs11-helper)
     'MBEDTLS_PLATFORM_NO_STD_FUNCTIONS', # removes a feature
+    'MBEDTLS_PSA_ASSUME_EXCLUSIVE_BUFFERS', # removes a feature
     'MBEDTLS_PSA_CRYPTO_CONFIG', # toggles old/new style PSA config
     'MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG', # behavior change + build dependency
     'MBEDTLS_PSA_CRYPTO_KEY_ID_ENCODES_OWNER', # incompatible with USE_PSA_CRYPTO
@@ -200,7 +201,6 @@
     'MBEDTLS_TEST_NULL_ENTROPY', # removes a feature
     'MBEDTLS_X509_ALLOW_UNSUPPORTED_CRITICAL_EXTENSION', # influences the use of X.509 in TLS
     'MBEDTLS_ZLIB_SUPPORT', # build dependency (libz)
-    'MBEDTLS_PSA_ASSUME_EXCLUSIVE_BUFFERS', # removes a feature
 ])
 
 def is_seamless_alt(name):