psa_crypto_ecp: remove support for secp224k1

Since this curve is not supported in PSA (and it will not ever be
in the future), we save a few bytes.

Signed-off-by: Valerio Setti <valerio.setti@nordicsemi.no>
diff --git a/library/psa_crypto_ecp.c b/library/psa_crypto_ecp.c
index 4d9a59b..61c9414 100644
--- a/library/psa_crypto_ecp.c
+++ b/library/psa_crypto_ecp.c
@@ -77,14 +77,9 @@
         case PSA_ECC_FAMILY_SECP_K1:
             switch (*bits) {
                 case 192:
+                /* secp224k1 is not and will not be supported in PSA (#3541). */
                 case 256:
                     return PSA_SUCCESS;
-                /* secp224k1 is not and will not be supported in PSA (#3541).
-                 * Note: secp224k1 has 224-bit coordinates but 225-bit private
-                 * keys which are rounded up to 232 for their representation. */
-                case 224:
-                case 232:
-                    return PSA_ERROR_NOT_SUPPORTED;
             }
             break;
     }