irqchip/riscv-intc: Add missing free() callback in riscv_intc_domain_ops

The irq_domain_free_irqs() helper requires that the irq_domain_ops->free
callback is implemented. Otherwise, the kernel reports the warning message
"NULL pointer, cannot free irq" when irq_dispose_mapping() is invoked to
release the per-HART local interrupts.

Set irq_domain_ops->free to irq_domain_free_irqs_top() to cure that.

Fixes: 832f15f ("RISC-V: Treat IPIs as normal Linux IRQs")
Signed-off-by: Nick Hu <nick.hu@sifive.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://patch.msgid.link/20251114-rv-intc-fix-v1-1-a3edd1c1a868@sifive.com

Author: nick650823

drivers/irqchip/irq-riscv-intc.c

@@ -166,7 +166,8 @@ static int riscv_intc_domain_alloc(struct irq_domain *domain,
 static const struct irq_domain_ops riscv_intc_domain_ops = {
 	.map	= riscv_intc_domain_map,
 	.xlate	= irq_domain_xlate_onecell,
-	.alloc	= riscv_intc_domain_alloc
+	.alloc	= riscv_intc_domain_alloc,
+	.free	= irq_domain_free_irqs_top,
 };
 
 static struct fwnode_handle *riscv_intc_hwnode(void)