Update kernel-ck-ubuntu

Added an option to set concurrency_level to the number of processors + X.
We now ensure that BFQ is there and enabled by default.
!!! I didn't test if lines 345-348 work properly, or make the Universe implode. Worst case scenario: it will mess the config in such way that the kernel won't compile, or if it does, maybe something will go wrong upon booting. Please test.