powerpc/mm: Eliminate not possible mmu features at compile time

[Michael Ellerman]

On Fri, 2018-11-16 at 17:08:03 UTC, Christophe Leroy wrote:
> Depending on the CONFIG selected, many of the MMU features are
> not possible. Lets only get the possible ones in MMU_FTRS_POSSIBLE.
> 
> This allows gcc to get rid at compile time of code related to
> not possible features.
> 
> Signed-off-by: Christophe Leroy <christophe.leroy at c-s.fr>

Applied to powerpc next, thanks.

https://git.kernel.org/powerpc/c/712877f8740471d96f703647d813d8

cheers