Bug 997469: switch kitkat emulator kernel to b2g-4.4.2_r1 branch

Change-Id: I089dfb4a44b54c95c2a346bee31d69fcb0919133
Merge pull request #178 from vicamo/bugzilla/997469/update-kk-qemu-kernel-4.4.2_r1

Bug 997469: switch kitkat emulator kernel to b2g-4.4.2_r1 branch. r=mwu