powerpc/mm: Remove flush_all_mm, local_flush_all_mm

powerpc/mm: Remove flush_all_mm, local_flush_all_mm

These functions were introduced for "cxl: Enable global TLBIs for cxl
contexts" [1], which ended up using them for Radix only. They were never
implemented on Hash (and creating an implementation appears to be
difficult), so nothing can actually rely on them.

They behave differently to the existing surrounding functions too, in
that they actually need to do something on Hash. The other functions
are primarily for use in generic code that expects their definitions,
but Hash updates the TLB during PTE updates.

After replacing the only usage with the Radix specific version, there
are no more users of these functions, and given they are not implemented
anyway it is safe to delete them.

[1]: https://patchwork.ozlabs.org/project/linuxppc-dev/patch/20170903181513.29635-1-fbarrat@linux.vnet.ibm.com/

Signed-off-by: Benjamin Gray <bgray@linux.ibm.com>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20221109045112.187069-7-bgray@linux.ibm.com