Did not see a response to the last version.

This patch enables TCP keepalives on VNC connections and TCP-based char
devices.

Default parameters have keep alive probes sent after 60-seconds of idle
time. Probes are sent every 12 seconds with the connection resetting
after 5 failed probes (ie., connection is closed if no response received
in 60-seconds).

Changes v2 -> v3
Removed duplicate definition and fixed typo in comments.

Signed-off-by: David Ahern <dsahern@gmail.com>


david