Revert "mm/hugetlb: add folio_hstate()"

This reverts commit 6b27a1f2 which is
commit e51da3a9 upstream.

It breaks the Android kernel abi and can be brought back in the future
in an abi-safe way if it is really needed.

Bug: 161946584
Change-Id: I431cd23e83455c445568dc8dd589915bdb6594c4
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>