pinctrl: cherryview: Trigger hwirq0 for interrupt-lines without a mapping

Commit bdfbef2d ("pinctrl: cherryview: Don't use selection 0 to mark
an interrupt line as unused") made the code properly differentiate
between unset vs (hwirq) 0 entries in the GPIO-controller interrupt-line
to GPIO pinnumber/hwirq mapping.

This is causing some boards to not boot. This commit restores the old
behavior of triggering hwirq 0 when receiving an interrupt on an
interrupt-line for which there is no mapping.

Fixes: bdfbef2d ("pinctrl: cherryview: Don't use selection 0 to mark an interrupt line as unused")
Reported-and-tested-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Link: https://lore.kernel.org/r/20220104164238.253142-1-hdegoede@redhat.comSigned-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/pinctrl/intel/pinctrl-cherryview.c

@@ -1471,8 +1471,9 @@ static void chv_gpio_irq_handler(struct irq_desc *desc)
 
 		offset = cctx->intr_lines[intr_line];
 		if (offset == CHV_INVALID_HWIRQ) {
-			dev_err(dev, "interrupt on unused interrupt line %u\n", intr_line);
-			continue;
+			dev_warn_once(dev, "interrupt on unmapped interrupt line %u\n", intr_line);
+			/* Some boards expect hwirq 0 to trigger in this case */
+			offset = 0;
 		}
 
 		generic_handle_domain_irq(gc->irq.domain, offset);