[mclag]: Added marvell-teralynx to port isolation grp support list (sonic-net#3946)

What I did
Added marvell-teralynx platform to port isolation group supported list in mclaglink.cpp.

Why I did it
The MCLAG port isolation configuration is guarded by a platform check in mclagsyncd. If the platform name is not in supported list, mclagsyncd tries to create MCLAG ACL table, using the peer link as the source port and the portchannel's in the domain as destination ports, instead of creating a port isolation group.

Since marvell-teralynx supports port isolation group objects, it has been added to the list of supported platforms.

Author: rminnikanti

mclagsyncd/mclaglink.cpp

@@ -193,7 +193,8 @@ void MclagLink::setPortIsolate(char *msg)
         BRCM_PLATFORM_SUBSTRING,
         BFN_PLATFORM_SUBSTRING,
         CTC_PLATFORM_SUBSTRING,
-        MRVL_PRST_PLATFORM_SUBSTRING
+        MRVL_PRST_PLATFORM_SUBSTRING,
+        MRVL_TL_PLATFORM_SUBSTRING
     };
 
     const char *platform = getenv("platform");

mclagsyncd/mclaglink.h

@@ -55,6 +55,7 @@
 #define BFN_PLATFORM_SUBSTRING  "barefoot"
 #define CTC_PLATFORM_SUBSTRING  "centec"
 #define MRVL_PRST_PLATFORM_SUBSTRING "marvell-prestera"
+#define MRVL_TL_PLATFORM_SUBSTRING   "marvell-teralynx"
 
 using namespace std;