hw/intc: Fix LoongArch ipi device emulation

hw/intc: Fix LoongArch ipi device emulation

In ipi_send function, it should not to set irq before
writing data to dest cpu iocsr space, as the irq will
trigger after data writing.
When call this function 'address_space_stl()', it will
trigger loongarch_ipi_writel(), the addr arg is 0x1008
('CORE_SET_OFF'), and qemu_irq_raise will be called in
this case.

Signed-off-by: Xiaojuan Yang <yangxiaojuan@loongson.cn>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220930095139.867115-3-yangxiaojuan@loongson.cn>
Signed-off-by: Song Gao <gaosong@loongson.cn>