[device][accton]: Update for AS7326-56X complying the BCM SAI 3.5.3.1m-26 (#3830)

* [device][accton]: Update for AS7326-56X complying the Broadcom SAI latest version 3.5.3.1m-26
* Update Accton-AS7326-56X to adapt xxx.config.bcm based on the latest update of Device-Specific File Directory Structure.
* Update Accton-AS7326-56X LED BIN complying the Broadcom SAI latest version 3.5.3.1m-26
Signed-off-by: polly_hsu@edge-core.com
* [device][accton]: Merge the SDK config with #3103 (Fix Accton as7326 port breakouk)
Signed-off-by: Polly Hsu <pollyhsu2git@gmail.com>

device/accton/x86_64-accton_as7326_56x-r0/Accton-AS7326-56X/sai.profile

@@ -1 +1 @@
-SAI_INIT_CONFIG_FILE=/etc/bcm/td3-as7326-48x25G+8x100G.config.bcm
+SAI_INIT_CONFIG_FILE=/usr/share/sonic/hwsku/td3-as7326-48x25G+8x100G.config.bcm

device/accton/x86_64-accton_as7326_56x-r0/Accton-AS7326-56X/td3-as7326-48x25G+8x100G.config.bcm

@@ -17,6 +17,7 @@ l2xmsg_mode=1
 bcm_num_cos=8
 bcm_stat_interval=2000000
 cdma_timeout_usec=3000000
+ifp_inports_support_enable=1
 ipv6_lpm_128b_enable=0x1
 l3_max_ecmp_mode=1
 l3_alpm_enable=2
@@ -24,11 +25,13 @@ lpm_scaling_enable=0
 max_vp_lags=0
 miim_intr_enable=0
 module_64ports=1
+port_flex_enable=1
 schan_intr_enable=0
 stable_size=0x5500000
 tdma_timeout_usec=3000000
 skip_L2_USER_ENTRY=0
 bcm_tunnel_term_compatible_mode=1
+l3_alpm_ipv6_128b_bkt_rsvd=1
 
 dport_map_port_1=6
 dport_map_port_2=2

device/accton/x86_64-accton_as7326_56x-r0/led_proc_init.soc

@@ -0,0 +1,6 @@
+#led auto off
+#led stop
+m0 load 0 0x0 /usr/share/sonic/platform/linkscan_led_fw.bin
+m0 load 0 0x3800 /usr/share/sonic/platform/custom_led.bin
+led auto on
+led start