target/hppa: Allow read-access to PSW with rsm 0,reg instruction

target/hppa: Allow read-access to PSW with rsm 0,reg instruction

HP-UX 11 and HP ODE tools use the "rsm 0,%reg" instruction in not priviledged
code paths to get the current PSW flags. The constant 0 means that no bits of
the PSW shall be reset, so this is effectively a read-only access to the PSW.
Allow this read-only access even for not privileged code.

Signed-off-by: Helge Deller <deller@gmx.de>
Acked-by: Richard Henderson <richard.henderson@linaro.org>