net: mvneta: make tx buffer array agnostic

[ Upstream commit 9e58c8b410650b5a6eb5b8fad8474bd8425a4023 ]

Allow tx buffer array to contain both skb and xdp buffers in order to
enable xdp frame recycling adding XDP_TX verdict support

Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Stable-dep-of: 2960a2d33b02 ("net: mvneta: fix potential double-frees in mvneta_txq_sw_deinit()")
Signed-off-by: Sasha Levin <sashal@kernel.org>