crypto_config.h: Don't list mechanisms that are not implemented

Don't list mechanisms that are not implemented in
`include/psa/crypto_config.h`, even commented out. Uncommenting them
wouldn't help anyway: they don't work. Having them listed, even commented
out, causes `find_dependencies_not_implemented()` in `psa_test_case.py` to
consider those mechanisms to be implemented, and thus causes
`generate_psa_tests.py` to generate test cases that cannot be executed.

The affected mechanisms are:

* `PSA_ALG_CBC_MAC` (`PSA_WANT_ALG_CBC_MAC`)
* `PSA_ALG_XTS` (`PSA_WANT_ALG_XTS`)
* `PSA_ECC_FAMILY_SECP_K1` 224-bit (`PSA_WANT_ECC_SECP_K1_224`)

Also remove the affected mechanisms from configuration adjustment files,
since that is code that can never be triggered.

There were already no generated test cases for SECP224K1 because
`PSA_WANT_ECC_SECP_K1_224` was already detected as a dependency that cannot
be implemented, because that is not a valid size: PSA defines SECP224K1 as
225-bit, and `crypto_knowledge.py` follows suite, so `generate_psa_tests.py`
saw `PSA_WANT_ECC_SECP_K1_225` in its enumeration but skipped it because it
was never mentioned in `crypto_config.h`.

This causes generated PSA tests to no longer include positive test cases for
`PSA_ALG_CBC_MAC` and `PSA_ALG_XTS`.

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
diff --git a/scripts/config.py b/scripts/config.py
index ef13062..957127e 100755
--- a/scripts/config.py
+++ b/scripts/config.py
@@ -48,8 +48,6 @@
     return True
 
 PSA_UNSUPPORTED_FEATURE = frozenset([
-    'PSA_WANT_ALG_CBC_MAC',
-    'PSA_WANT_ALG_XTS',
     'PSA_WANT_KEY_TYPE_RSA_KEY_PAIR_DERIVE',
     'PSA_WANT_KEY_TYPE_DH_KEY_PAIR_DERIVE'
 ])
@@ -59,13 +57,8 @@
     'PSA_WANT_KEY_TYPE_RSA_KEY_PAIR'
 ])
 
-PSA_UNSTABLE_FEATURE = frozenset([
-    'PSA_WANT_ECC_SECP_K1_224'
-])
-
 EXCLUDE_FROM_CRYPTO = PSA_UNSUPPORTED_FEATURE | \
-                      PSA_DEPRECATED_FEATURE | \
-                      PSA_UNSTABLE_FEATURE
+                      PSA_DEPRECATED_FEATURE
 
 # The goal of the full configuration is to have everything that can be tested
 # together. This includes deprecated or insecure options. It excludes:
@@ -357,8 +350,6 @@
 
         if name in PSA_UNSUPPORTED_FEATURE:
             raise ValueError(f'Feature is unsupported: \'{name}\'')
-        if name in PSA_UNSTABLE_FEATURE:
-            raise ValueError(f'Feature is unstable: \'{name}\'')
 
         if name not in self.settings:
             self._get_configfile().templates.append((name, '', '#define ' + name + ' '))