**- Why I did it**
Converted two SP model to single pool model and modified the buffer size.
**- How I did it**
Changed buffer_default settings for all the DellEMC Z9264f HWSKU's.
**- How to verify it**
Check SP register values in NPU shell.
**- Which release branch to backport (provide reason below if selected)**
Need to be cherry picked for 201911 branch.
as needed by SAI 3.7 and above. Without this change
Warmboot fails from 3.5 to 3.7 as Braodcoam Datastructure
gets corrupted after warm-boot.
Signed-off-by: Abhishek Dosi <abdosi@microsoft.com>