net: thunderx: Set watchdog timeout value

If a txq (SQ) remains in stopped state after this timeout its
considered as stuck and interface is reinited.

Signed-off-by: Sunil Goutham <sgoutham@cavium.com>
Signed-off-by: Aleksey Makarov <aleksey.makarov@caviumnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>