target/hppa: Only set PSW 'M' bit on reset

On reset:

  "All PSW bits except the M bit is reset. The M bit is set."

Commit 1a19da0da44 ("target/hppa: Fill in hppa_cpu_do_interrupt /
hppa_cpu_exec_interrupt") inadvertently set the W bit at RESET,
remove it and set the M bit.

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Acked-by: Helge Deller <deller@gmx.de>
Message-Id: <20241231190620.24442-5-philmd@linaro.org>
1 file changed