hw/arm/bcm2835_peripherals: Correctly wire the SYS_timer IRQs

hw/arm/bcm2835_peripherals: Correctly wire the SYS_timer IRQs

The SYS_timer is not directly wired to the ARM core, but to the
SoC (peripheral) interrupt controller.

Fixes: 0e5bbd74064 ("hw/arm/bcm2835_peripherals: Use the SYS_timer")
Reviewed-by: Luc Michel <luc.michel@greensocs.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-id: 20201010203709.3116542-5-f4bug@amsat.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>