The yocto source and images for R13.1.1. are downloaded from the source.sierrawireless.com
https://source.sierrawireless.com/resources/airprime/software/wp76xx/wp76xx-firmware-release-13,-d-,1,-d-,1-components/#sthash.mu1ldr0f.hq9igaq4.dpbs
Further the error 68 as seen on your UART console is also seen on FDT tool cmd line.
Below are the files requested:
yoctocwetool.sh (9.2 KB)
nand_ids.c (10.6 KB)
qpic_nand.c (63.2 KB)
Let me know if you need any further information.