irqchip/aslint-sswi: Resolve hart index

Resolve hart index according to assignment in the "riscv,hart-indexes"
property as defined in the specification [1]

Signed-off-by: Vladimir Kondratiev <vladimir.kondratiev@mobileye.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/20250612143911.3224046-6-vladimir.kondratiev@mobileye.com
Link: https://github.com/riscvarchive/riscv-aclint [1]