irqchip/gic: Unify GIC priority definitions

LPIs use the same priority value as other GIC interrupts.

Make the GIC default priority definition visible to ITS implementation
and use this same definition for LPI priorities.

Tested-by: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: Julien Thierry <julien.thierry@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
index 4251d2d..db20e99 100644
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -68,7 +68,7 @@ static u32 lpi_id_bits;
 #define LPI_PROPBASE_SZ		ALIGN(BIT(LPI_NRBITS), SZ_64K)
 #define LPI_PENDBASE_SZ		ALIGN(BIT(LPI_NRBITS) / 8, SZ_64K)
 
-#define LPI_PROP_DEFAULT_PRIO	0xa0
+#define LPI_PROP_DEFAULT_PRIO	GICD_INT_DEF_PRI
 
 /*
  * Collection structure - just an ID, and a redistributor address to