sparc64: skip handshake for LDC channels in RAW mode

LDC channels in RAW mode does not provide any session management. No
handshake protocol is defined for LDC channels in RAW mode. It's
therefore skipped.

Signed-off-by: Jagannathan Raman <jag.raman@oracle.com>
Reviewed-by: Liam Merwick <liam.merwick@oracle.com>
Reviewed-by: Shannon Nelson <shannon.nelson@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>