irqchip/gic-v3: Prefix all pr_* messages by "GICv3: "

Currently, most of the pr_* messages in the GICv3 driver don't have a
prefix.  Add one to make clear where the messages come from.

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-v3.c b/drivers/irqchip/irq-gic-v3.c
index 5b7d3c2..6dc6f03 100644
--- a/drivers/irqchip/irq-gic-v3.c
+++ b/drivers/irqchip/irq-gic-v3.c
@@ -15,6 +15,8 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
+#define pr_fmt(fmt)	"GICv3: " fmt
+
 #include <linux/acpi.h>
 #include <linux/cpu.h>
 #include <linux/cpu_pm.h>