net: mvpp2: do not disable GMAC padding

commit e749aca84b10f3987b2ee1f76e0c7d8aacc5653c upstream.

Short fragmented packets may never be sent by the hardware when padding
is disabled. This patch stop modifying the GMAC padding bits, to leave
them to their reset value (disabled).

Fixes: 3919357f ("net: mvpp2: initialize the GMAC when using a port")
Signed-off-by: Yan Markman <ymarkman@marvell.com>
[Antoine: commit message]
Signed-off-by: Antoine Tenart <antoine.tenart@free-electrons.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>