target/hppa: Restore unwind_breg before calculating ior

target/hppa: Restore unwind_breg before calculating ior

When calculating the IOR for the exception handlers, the current
unwind_breg value is needed on 64-bit hppa machines.
Restore that value by calling cpu_restore_state() earlier, which in turn
calls hppa_restore_state_to_opc() which restores the unwind_breg for the
current instruction.

Signed-off-by: Helge Deller <deller@gmx.de>
Fixes: 3824e0d643f3 ("target/hppa: Export function hppa_set_ior_and_isr()")
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>