Hello Viral Vasa,
There is not a library per se, but the recommendation is to extract the symbol and footprint from the Design Files of the i.MX6ULL EVK, which is in Allegro format. You can download these files from the link below (you may need to login to download them)
https://www.nxp.com/downloads/en/schematics/MCIMX6ULL-EVK-DESIGNFILES.zip
My apologies for the inconvenience! II hope this helps!
Regards,