Revert "lowmemorykiller.c: LMK from the latest Linux Kernel"

This reverts commit 3db24c9a6e2ac8a82b815cf2554aad0dd7608cb0.
Revert "Revert "lowmemorykiller.c: LMK from the latest Linux Kernel""

This reverts commit e8ff40a15c3128501d51a387189c82200ff5d827.
Revert "ARM: support XZ compressed kernels"

This reverts commit 2880161e68b2bd24f22e15e309e4727f3f6c6d4f.
Revert "update LZO"

This reverts commit 75051ae791c5591023fa084d7b64d2afe467ce55.
Revert " Enable UNALIGNED_ACCESS for the new LZO algorithm to use. LZO decromp…"

This reverts commit 00bab43d5ccff7168523580e57f4febdef79f3a2.