irqchip: Return -EPERM for reserved IRQs

The irqdomain core will report a log message for any attempted map call
that fails unless the error code is -EPERM. This patch changes the
Versatile irq controller drivers to use -EPERM because it is normal for
a subset of the IRQ inputs to be marked as reserved on the various
Versatile platforms.
Signed-off-by: NGrant Likely <grant.likely@linaro.org>

drivers/irqchip/irq-versatile-fpga.c

@@ -119,7 +119,7 @@ static int fpga_irqdomain_map(struct irq_domain *d, unsigned int irq,
 
 	/* Skip invalid IRQs, only register handlers for the real ones */
 	if (!(f->valid & BIT(hwirq)))
-		return -ENOTSUPP;
+		return -EPERM;
 	irq_set_chip_data(irq, f);
 	irq_set_chip_and_handler(irq, &f->chip,
 				handle_level_irq);

drivers/irqchip/irq-vic.c

@@ -197,7 +197,7 @@ static int vic_irqdomain_map(struct irq_domain *d, unsigned int irq,
 
 	/* Skip invalid IRQs, only register handlers for the real ones */
 	if (!(v->valid_sources & (1 << hwirq)))
-		return -ENOTSUPP;
+		return -EPERM;
 	irq_set_chip_and_handler(irq, &vic_chip, handle_level_irq);
 	irq_set_chip_data(irq, v->base);
 	set_irq_flags(irq, IRQF_VALID | IRQF_PROBE);