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

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

irq_domain_alloc_fwnode() takes a parameter with the phys_addr_t type.
Currently we pass acpi_pchpic->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 platforms.

Also use readl() to read vec_count because readq() is only available on
64BIT platform.

[ tglx: Make the cast explicit and use the casted address as argument for
  	pch_pic_init() which takes a phys_addr_t as well. Fixup coding
  	style. More sigh... ]

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/20260113085940.3344837-7-chenhuacai@loongson.cn