hw/intc/riscv_aplic: Zero init APLIC internal state

hw/intc/riscv_aplic: Zero init APLIC internal state

Since g_new is used to initialize the RISCVAPLICState->state structure,
in some case we get behavior that is not as expected. This patch
changes this to g_new0, which allows to initialize the APLIC in the correct state.

Signed-off-by: Ivan Klokov <ivan.klokov@syntacore.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Message-Id: <20230413133432.53771-1-ivan.klokov@syntacore.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>