Linksys Northstar partitioning support

configname: CONFIG_MTD_OF_PARTS_LINKSYS_NS

Linux Kernel Configuration
└─>Device Drivers
└─>Memory Technology Device (MTD) support
└─>Partition parsers
└─>Linksys Northstar partitioning support
In linux kernel since version 5.2 (release Date: 2019-07-07)  
This provides partitions parser for Linksys devices based on Broadcom
Northstar architecture. Linksys commonly uses fixed flash layout with
two "firmware" partitions. Currently used firmware has to be detected
using CFE environment variable.