Port indexes of front panel ports are not contiguous in multi-asic because we didn't distiguish between
front panel and internal ports, e.g., recycle ports. Fix this by assigning index to front panel port first
and then internal ports.
For 7800 LCs, set LAG mode to support 1024 number of 16-member system
LAGs.
Why I did it
The SOC property changes are necessary to match #10519 which increases the number of system LAG IDs to 1024.
Description for the changelog
For 7800 LCs, set LAG mode to support 1024 number of 16-member system
LAGs.
