x86: Move UCLASS_IRQ into a separate file

Update this uclass to support the needs of the Apollo Lake ITSS. It
supports four operations.

Move the uclass into a separate directory so that sandbox can use it too.
Add a new Kconfig to control it and enable this on x86.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>

drivers/misc/irq-uclass.c

@@ -0,0 +1,53 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2015, Bin Meng <bmeng.cn@gmail.com>
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <irq.h>
+
+int irq_route_pmc_gpio_gpe(struct udevice *dev, uint pmc_gpe_num)
+{
+	const struct irq_ops *ops = irq_get_ops(dev);
+
+	if (!ops->route_pmc_gpio_gpe)
+		return -ENOSYS;
+
+	return ops->route_pmc_gpio_gpe(dev, pmc_gpe_num);
+}
+
+int irq_set_polarity(struct udevice *dev, uint irq, bool active_low)
+{
+	const struct irq_ops *ops = irq_get_ops(dev);
+
+	if (!ops->set_polarity)
+		return -ENOSYS;
+
+	return ops->set_polarity(dev, irq, active_low);
+}
+
+int irq_snapshot_polarities(struct udevice *dev)
+{
+	const struct irq_ops *ops = irq_get_ops(dev);
+
+	if (!ops->snapshot_polarities)
+		return -ENOSYS;
+
+	return ops->snapshot_polarities(dev);
+}
+
+int irq_restore_polarities(struct udevice *dev)
+{
+	const struct irq_ops *ops = irq_get_ops(dev);
+
+	if (!ops->restore_polarities)
+		return -ENOSYS;
+
+	return ops->restore_polarities(dev);
+}
+
+UCLASS_DRIVER(irq) = {
+	.id		= UCLASS_IRQ,
+	.name		= "irq",
+};