parisc: Avoid clobbering the C/B bits in the PSW with tophys and tovirt macros

Use add,l to avoid clobbering the C/B bits in the PSW.

Signed-off-by: John David Anglin <dave.anglin@bell.net>
Signed-off-by: Helge Deller <deller@gmx.de>
Cc: stable@vger.kernel.org # v5.10+