Remove over-specific RFC references

Rely on general reference to IANA documentation
diff --git a/include/psa/crypto_types.h b/include/psa/crypto_types.h
index fbbb737..dfc17a9 100644
--- a/include/psa/crypto_types.h
+++ b/include/psa/crypto_types.h
@@ -75,7 +75,6 @@
  * TLS Supported Groups Registry (formerly known as the
  * TLS EC Named Curve Registry)
  * https://www.iana.org/assignments/tls-parameters/tls-parameters.xhtml#tls-parameters-8
- * The values are defined by RFC 8422 and RFC 7027.
  *
  * This specification defines identifiers for some of the curves in the IANA
  * registry. Implementations that support other curves that are in the IANA
@@ -102,7 +101,6 @@
  * TLS Supported Groups Registry (formerly known as the
  * TLS EC Named Curve Registry)
  * https://www.iana.org/assignments/tls-parameters/tls-parameters.xhtml#tls-parameters-8
- * The values are defined by RFC 7919.
  *
  * This specification defines identifiers for some of the groups in the IANA
  * registry. Implementations that support other groups that are in the IANA