Revert "mm/Kconfig: add ZSWAP writeback options"

This reverts commit 6c05192f4403602be86288a31aba82d8b5b2956b.
Revert "Backport vnswap/frontswap/zswap to Moto G"

This reverts commit be816b484882b9fe2a47509e0433d7ae5e778164.