hw/arm/spitz: Fix reset handling

hw/arm/spitz: Fix reset handling

Using the CPU reset handler for resets triggered by writing into
gpio pins other than GPIO01 is not appropriate and does not work,
since the reset triggered by writing into GPIO01 is configurable.
Use a separate reset handler for spitz to reset the entire system
and not just the CPU.

Signed-off-by: Guenter Roeck <[email protected]>
Message-id: 1477597646[email protected]
Reviewed-by: Peter Maydell <[email protected]>
Signed-off-by: Peter Maydell <[email protected]>