Enable tunnel in default for Accton-AS5835-54X

Author: iris00522

device/accton/x86_64-accton_as5835_54x-r0/Accton-AS5835-54X/mv2-as5835-48x10G+6x100G.config.bcm

@@ -41,6 +41,15 @@ skip_L2_USER_ENTRY=0
 bcm_tunnel_term_compatible_mode=1
 l3_alpm_ipv6_128b_bkt_rsvd=1
 
+#vxlan
+use_all_splithorizon_groups=1
+riot_enable=1
+sai_tunnel_support=1
+riot_overlay_l3_intf_mem_size=4096
+riot_overlay_l3_egress_mem_size=32768
+riot_overlay_ecmp_resilient_hash_size=16384
+flow_init_mode=1
+
 #FC0
 dport_map_port_1=1
 dport_map_port_2=2