powerpc/mm: Switch obsolete dssall to .long

commit d51f86cf upstream.

The dssall ("Data Stream Stop All") instruction is obsolete altogether
with other Data Cache Instructions since ISA 2.03 (year 2006).

LLVM IAS does not support it but PPC970 seems to be using it.
This switches dssall to .long as there is no much point in fixing LLVM.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211221055904.555763-6-aik@ozlabs.ru


[sudip: adjust context]
Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>