SECP224K1 is not yet supported via the PSA API

Filed as https://github.com/ARMmbed/mbedtls/issues/3541. In the
meantime, disable the feature.

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
diff --git a/include/mbedtls/config_psa.h b/include/mbedtls/config_psa.h
index c46ed56..39a5001 100644
--- a/include/mbedtls/config_psa.h
+++ b/include/mbedtls/config_psa.h
@@ -678,7 +678,8 @@
 #define PSA_WANT_ECC_SECP_K1_192
 #endif
 
-#if defined(MBEDTLS_ECP_DP_SECP224K1_ENABLED)
+/* SECP224K1 is buggy via the PSA API (https://github.com/ARMmbed/mbedtls/issues/3541) */
+#if 0 && defined(MBEDTLS_ECP_DP_SECP224K1_ENABLED)
 #define MBEDTLS_PSA_BUILTIN_ECC_SECP_K1_224 1
 #define PSA_WANT_ECC_SECP_K1_224
 #endif