[Arista7050cx3] TD3 SKU changes for pg headroom value after interop t…

…esting with cisco 8102 (sonic-net#11901)

Why I did it
After PFC interop testing between 8102 and 7050cx3, data packet losses were observed on the Rx ports of the 7050cx3 (inflow from 8102) during testing. This was primarily due to the slower response times to react to PFC pause packets for the 8102, when receiving such frames from neighboring devices. To solve for the packet drops, the 7050cx3 pg headroom size has to be increased to 160kB.

How I did it
Modified the xoff threshold value to 160kB in the pg_profile file to allow for the buffer manager to read that value when building the image, and configuring the device

How to verify it
run "mmuconfig -l" once image is built


Signed-off-by: dojha <devojha@microsoft.com>

device/arista/x86_64-arista_7050cx3_32s/Arista-7050CX3-32S-C32/pg_profile_lookup.ini

@@ -1,8 +1,8 @@
 # PG lossless profiles.
 # speed cable size    xon  xoff threshold xon_offset
-  50000  5m   4608    4608 33792   0        4608
- 100000  5m   4608    4608 49408   0        4608
-  50000  40m  4608    4608 36352   0        4608
- 100000  40m  4608    4608 54528   0        4608
-  50000  300m 4608    4608 55296   0        4608
- 100000  300m 4608    4608 92672   0        4608
+  50000  5m   4608    4608 160000   0        4608
+ 100000  5m   4608    4608 160000   0        4608
+  50000  40m  4608    4608 160000   0        4608
+ 100000  40m  4608    4608 160000   0        4608
+  50000  300m 4608    4608 160000   0        4608
+ 100000  300m 4608    4608 160000   0        4608

device/arista/x86_64-arista_7050cx3_32s/Arista-7050CX3-32S-D48C8/pg_profile_lookup.ini

@@ -1,8 +1,8 @@
 # PG lossless profiles.
 # speed cable size    xon  xoff threshold xon_offset
-  50000  5m   4608    4608 79872   0        4608
- 100000  5m   4608    4608 54528   0        4608
-  50000  40m  4608    4608 39936   0        4608
- 100000  40m  4608    4608 60416   0        4608
-  50000  300m 4608    4608 61440   0        4608
- 100000  300m 4608    4608 103680  0        4608
+  50000  5m   4608    4608 160000   0        4608
+ 100000  5m   4608    4608 160000   0        4608
+  50000  40m  4608    4608 160000   0        4608
+ 100000  40m  4608    4608 160000   0        4608
+  50000  300m 4608    4608 160000   0        4608
+ 100000  300m 4608    4608 160000   0        4608