octeontx2-af: Fix pause frame configuration

The current implementation's default Pause Forward setting is causing
unnecessary network traffic. This patch disables Pause Forward to
address this issue.

Fixes: 1121f6b0

 ("octeontx2-af: Priority flow control configuration support")
Signed-off-by: Hariprasad Kelam <hkelam@marvell.com>
Signed-off-by: Sunil Kovvuri Goutham <sgoutham@marvell.com>
Signed-off-by: David S. Miller <davem@davemloft.net>