QEMU allows qemu_irq lines to transfer arbitrary integers.  However
the convention is that for a simple IRQ line the values transferred
are always 0 and 1.  The A10 SD controller device instead assumes a
0-vs-non-0 convention, which happens to work with the interrupt
controller it is wired up to.

Coerce the value to boolean to follow our usual convention.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Message-id: 20230606104609.3692557-3-peter.maydell@linaro.org