octeontx2-pf: Fix fall-through warning for Clang

In preparation to enable -Wimplicit-fallthrough for Clang, fix a warning
by explicitly adding a break statement instead of letting the code fall
through to the next case.

Link: https://github.com/KSPP/linux/issues/115
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Link: https://lore.kernel.org/r/20210528202225.GA39855@embeddedor
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/ethernet/marvell/octeontx2/nic/otx2_flows.c

@@ -551,6 +551,7 @@ static int otx2_prepare_ipv6_flow(struct ethtool_rx_flow_spec *fsp,
 			req->features |= BIT_ULL(NPC_IPPROTO_AH);
 		else
 			req->features |= BIT_ULL(NPC_IPPROTO_ESP);
+		break;
 	default:
 		break;
 	}