Strip netkvm from 'optional files'

Since we recently imported the netkvm driver into our sources via 0.4.14-dev-1545-g4c37757
wouldn't it be a good idea to strip it from the optional modules that can be baken into our isos manually?
We would then reduce the "Optional file skipped (does not exist):"-buildspam a bit upon "ninja bootcd".

To be distinct: This is my proposal strip_netkvm.patch
extravert34 would you agree to that change, or do you see any drawbacks?