eth: use maxpeers from p2p layer instead of extra config

cmd/utils/flags.go

@@ -949,10 +949,6 @@ func SetEthConfig(ctx *cli.Context, stack *node.Node, cfg *eth.Config) {
 		cfg.NetworkId = ctx.GlobalUint64(NetworkIdFlag.Name)
 	}
 
-	// Ethereum needs to know maxPeers to calculate the light server peer ratio.
-	// TODO(fjl): ensure Ethereum can get MaxPeers from node.
-	cfg.MaxPeers = ctx.GlobalInt(MaxPeersFlag.Name)
-
 	if ctx.GlobalIsSet(CacheFlag.Name) {
 		cfg.DatabaseCache = ctx.GlobalInt(CacheFlag.Name)
 	}