Something appears to be off between the 64-bit CPU, the 32-bit PDC
(SeaBIOS-hppa firmware), and the 64-bit kernel in addressing the
power button address in high-mapped firmware memory.

Use a 32-bit value at PAGE0->pad0[4] instead.

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