parisc: Remove ordered stores from syscall.S

Now that we use a sync prior to releasing the locks in syscall.S, we don't need
the PA 2.0 ordered stores used to release some locks.  Using an ordered store,
potentially slows the release and subsequent code.

There are a number of other ordered stores and loads that serve no purpose.  I
have converted these to normal stores.

Signed-off-by: John David Anglin <dave.anglin@bell.net>
Cc: stable@vger.kernel.org # 4.0+
Signed-off-by: Helge Deller <deller@gmx.de>