net: systemport: Correctly set TSB endian for host

Similarly to how we configure the RSB (Receive Status Block) we also
need to set the TSB (Transmit Status Block) based on the host endian.
This was missing from the commit indicated below.

Fixes: 389a06bc ("net: systemport: Set correct RSB endian bits based on host")
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>