Revert "busybox: use busybox 1.20.2 from perseus kernel"

This reverts commit a7b805ba0cb8ddc9ce758255d3980a2463f180b9.
Revert "Revert "enable uksm by default""

This reverts commit 53d928360ad2b2c6d4e6f9a8004efc19997b344b.
Revert "Revert "defconfig: enable lz4 zram compression""

This reverts commit 6077bcb9eb831015df97cf67d4058b5b94f05960.