SUNRPC: Remove redundant crypto Kconfig dependencies

SUNRPC: Remove redundant crypto Kconfig dependencies

With all per-message crypto operations now routed through
crypto/krb5, rpcsec_gss_krb5 no longer calls individual
crypto algorithms directly. The CRYPTO_KRB5 symbol already
selects CRYPTO_SKCIPHER and CRYPTO_HASH (the latter
transitively via CRYPTO_HMAC).

Drop the top-level select CRYPTO_SKCIPHER and select
CRYPTO_HASH from RPCSEC_GSS_KRB5, as these are redundant
with CRYPTO_KRB5's own dependencies.

Assisted-by: Claude:claude-opus-4-6
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Acked-by: Anna Schumaker <anna.schumaker@hammerspace.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>