It's a bit surprising that e.g. TLS_ECDHE_PSK_WITH_AES_128_CBC_SHA,
when negotiated in TLS 1.2, would use the TLS PRF with SHA-1 as the
hash function. Note that e.g. TLS_DHE_PSK_WITH_AES_128_CBC_SHA (from
RFC 4279) would in this situation use the TLS PRF with SHA-256.
My suggestion would be to say that all these cipher suites can be
negotiated with any TLS version; when used with TLS <1.2, they use
the PRF from that version; when used with TLS >=1.2, they use the
TLS PRF with SHA-256 or SHA-384. (In other words: they'd work the
same way as the cipher suites in RFC 4492/4279/4785.)
