hw/intc/allwinner-a10-pic: Handle IRQ levels other than 0 or 1

hw/intc/allwinner-a10-pic: Handle IRQ levels other than 0 or 1

In commit 2c5fa0778c3b430 we fixed an endianness bug in the Allwinner
A10 PIC model; however in the process we introduced a regression.
This is because the old code was robust against the incoming 'level'
argument being something other than 0 or 1, whereas the new code was
not.

In particular, the allwinner-sdhost code treats its IRQ line
as 0-vs-non-0 rather than 0-vs-1, so when the SD controller
set its IRQ line for any reason other than transmit the
interrupt controller would ignore it. The observed effect
was a guest timeout when rebooting the guest kernel.

Handle level values other than 0 or 1, to restore the old
behaviour.

Fixes: 2c5fa0778c3b430 ("hw/intc/allwinner-a10-pic: Don't use set_bit()/clear_bit()")
Cc: qemu-stable@nongnu.org
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: 20230606104609.3692557-2-peter.maydell@linaro.org