parisc/pgtable: Do not drop upper 5 address bits of physical address

commit 166b0110d1ee53290bd11618df6e3991c117495a upstream.

When calculating the pfn for the iitlbt/idtlbt instruction, do not
drop the upper 5 address bits. This doesn't seem to have an effect
on physical hardware which uses less physical address bits, but in
qemu the missing bits are visible.

Signed-off-by: Helge Deller <deller@gmx.de>
Cc:  <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>