irqchip/loongson-pch-msi: Adjust irqchip driver for 32BIT/64BIT

irqchip/loongson-pch-msi: Adjust irqchip driver for 32BIT/64BIT

irq_domain_alloc_fwnode() takes a parameter with the phys_addr_t type.
Currently the code passe acpi_pchmsi->msg_address to it.

This can only work on 64BIT platform because its type is u64, so cast it to
phys_addr_t and then the driver works on both 32BIT and 64BIT platform.

[ tglx: Make the cast explicit and fixup coding style. ]

Co-developed-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Link: https://patch.msgid.link/20260113085940.3344837-6-chenhuacai@loongson.cn