Revert "def: CONFIG_DYNAMIC_PAGE_WRITEBACK"

This reverts commit 47292099259c00d209bb06bfea5e0fde2200ad87.
Revert "mm: add DYNAMIC_PAGE_WRITEBACK"

This reverts commit 2b2a1e14775d0d4334ebe1e9d8e3ea21d9e9cecd.