pinctrl: cherryview: fix issues caused by dynamic gpio irqs mapping

New GPIO IRQs are allocated and mapped dynamically by default when
GPIO IRQ infrastructure is used by cherryview-pinctrl driver.
This causes issues on some Intel platforms [1][2] with broken BIOS which
hardcodes Linux IRQ numbers in their ACPI tables.

On such platforms cherryview-pinctrl driver should allocate and map all
GPIO IRQs at probe time.
Side effect - "Cannot allocate irq_descs @ IRQ%d, assuming pre-allocated\n"
can be seen at boot log.

NOTE. It still may fail if boot sequence will changed and some interrupt
controller will be probed before cherryview-pinctrl which will shift Linux IRQ
numbering (expected with CONFIG_SPARCE_IRQ enabled).

[1] https://bugzilla.kernel.org/show_bug.cgi?id=194945
[2] https://lkml.org/lkml/2017/9/28/153
Cc: Andy Shevchenko <[e-mail]>
Cc: Chris Gorman <[e-mail]>
Cc: Mika Westerberg <[e-mail]>
Cc: Heikki Krogerus <[e-mail]>
Signed-off-by: Grygorii Strashko <[e-mail]>
Reported-by: Chris Gorman <[e-mail]>
Reported-by: Mika Westerberg <[e-mail]>
Tested-by: Chris Gorman <[e-mail]>
Acked-by: Mika Westerberg <[e-mail]>
Signed-off-by: Linus Walleij <[e-mail]>

drivers/pinctrl/intel/pinctrl-cherryview.c

···
 	struct gpio_chip *chip = &pctrl->chip;
 	bool need_valid_mask = !dmi_check_system(chv_no_valid_mask);
 	int ret, i, offset;
+	int irq_base;
 
 	*chip = chv_gpio_chip;
 
···
 	/* Clear all interrupts */
 	chv_writel(0xffff, pctrl->regs + CHV_INTSTAT);
 
-	ret = gpiochip_irqchip_add(chip, &chv_gpio_irqchip, 0,
+	if (!need_valid_mask) {
+		irq_base = devm_irq_alloc_descs(pctrl->dev, -1, 0,
+						chip->ngpio, NUMA_NO_NODE);
+		if (irq_base < 0) {
+			dev_err(pctrl->dev, "Failed to allocate IRQ numbers\n");
+			return irq_base;
+		}
+	} else {
+		irq_base = 0;
+	}
+
+	ret = gpiochip_irqchip_add(chip, &chv_gpio_irqchip, irq_base,
 				   handle_bad_irq, IRQ_TYPE_NONE);
 	if (ret) {
 		dev_err(pctrl->dev, "failed to add IRQ chip\n");