Comment # 3 on bug 1082725 from Takashi Iwai

First off, try to boot both on working (the previous one) and broken (4.4.114)
kernels, and check the output of "modinfo i915 | grep file" in both cases.

If both point to */weak-updates/* path, it's OK.  If only one of them show the
different path (*/kernel/drivers/...), it's the problem.  Or if both show
*/kernel/drivers/*, it's also OK.

Once after that, try to boot 4.4.114 kernel with drm.debug=0x0e boot option. 
Give the kernel journal log at the crash.