This is the Halium adapted kernel for the Dell Venue 7840 (aka. Blackburn BB) and Dell Venue 7040 (Eaglespeak, EP).
This kernel originates from the Asus Zenfone 2 (ZE551ML) CM 7.1 kernel which is almost the same device internally.
Source: https://github.com/LineageOS/android_kernel_asus_moorefield (for license please see README)