hw/arm/exynos4210: Drop ext_gic_irq[] from Exynos4210Irq struct

hw/arm/exynos4210: Drop ext_gic_irq[] from Exynos4210Irq struct

The only time we use the ext_gic_irq[] array in the Exynos4210Irq
struct is during realize of the SoC -- we initialize it with the
input IRQs of the external GIC device, and then connect those to
outputs of other devices further on in realize (including in the
exynos4210_init_board_irqs() function).  Now that the ext_gic object
is easily accessible as s->ext_gic we can make the connections
directly from one device to the other without going via this array.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20220404154658.565020-10-peter.maydell@linaro.org