irqchip/gic-v2: Parse and export virtual GIC information

For now, the firmware tables are parsed 2 times: once in the GIC
drivers, the other timer when initializing the vGIC. It means code
duplication and make more tedious to add the support for another
firmware table (like ACPI).

Introduce a new structure and set of helpers to get/set the virtual GIC
information. Also fill up the structure for GICv2.

Signed-off-by: Julien Grall <julien.grall@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
diff --git a/drivers/irqchip/irq-gic-common.h b/drivers/irqchip/irq-gic-common.h
index fff697d..205e5fd 100644
--- a/drivers/irqchip/irq-gic-common.h
+++ b/drivers/irqchip/irq-gic-common.h
@@ -19,6 +19,7 @@
 
 #include <linux/of.h>
 #include <linux/irqdomain.h>
+#include <linux/irqchip/arm-gic-common.h>
 
 struct gic_quirk {
 	const char *desc;
@@ -35,4 +36,6 @@
 void gic_enable_quirks(u32 iidr, const struct gic_quirk *quirks,
 		void *data);
 
+void gic_set_kvm_info(const struct gic_kvm_info *info);
+
 #endif /* _IRQ_GIC_COMMON_H */