Give proper Dict type hints in crypto_knowledge.py

This prevents a return type error in a later function that uses the
dictionaries here properly typed.

Signed-off-by: David Horstmann <david.horstmann@arm.com>

scripts/mbedtls_dev/crypto_knowledge.py

@@ -20,7 +20,7 @@
 
 import enum
 import re
-from typing import FrozenSet, Iterable, List, Optional, Tuple
+from typing import FrozenSet, Iterable, List, Optional, Tuple, Dict
 
 from .asymmetric_key_data import ASYMMETRIC_KEY_DATA
 
@@ -148,7 +148,7 @@ def is_public(self) -> bool:
         'PSA_ECC_FAMILY_BRAINPOOL_P_R1': (160, 192, 224, 256, 320, 384, 512),
         'PSA_ECC_FAMILY_MONTGOMERY': (255, 448),
         'PSA_ECC_FAMILY_TWISTED_EDWARDS': (255, 448),
-    }
+    } # type: Dict[str, Tuple[int, ...]]
     KEY_TYPE_SIZES = {
         'PSA_KEY_TYPE_AES': (128, 192, 256), # exhaustive
         'PSA_KEY_TYPE_ARC4': (8, 128, 2048), # extremes + sensible
@@ -160,7 +160,7 @@ def is_public(self) -> bool:
         'PSA_KEY_TYPE_HMAC': (128, 160, 224, 256, 384, 512), # standard size for each supported hash
         'PSA_KEY_TYPE_RAW_DATA': (8, 40, 128), # sample
         'PSA_KEY_TYPE_RSA_KEY_PAIR': (1024, 1536), # small sample
-    }
+    } # type: Dict[str, Tuple[int, ...]]
     def sizes_to_test(self) -> Tuple[int, ...]:
         """Return a tuple of key sizes to test.