ACPI: EC: PM: s2idle: Extend GPE dispatching debug message

Add the "ACPI" string to the "EC GPE dispatched" message as it is
ACPI-related.

Signed-off-by: Rafael J. Wysocki <[e-mail]>

drivers/acpi/ec.c

···
 	 */
 	ret = acpi_dispatch_gpe(NULL, first_ec->gpe);
 	if (ret == ACPI_INTERRUPT_HANDLED) {
-		pm_pr_dbg("EC GPE dispatched\n");
+		pm_pr_dbg("ACPI EC GPE dispatched\n");
 
 		/* Flush the event and query workqueues. */
 		acpi_ec_flush_work();