ACPICA: Remove obsolete debug levels (WARN and ERROR)

Removed ACPI_DB_WARN and ACPI_DB_ERROR. These debug levels were
made obsolete by the ACPI_WARNING and ACPI_ERROR/ACPI_EXCEPTION
interfaces.  Also added ACPI_DB_EVENTS to correspond with the
existing ACPI_LV_EVENTS.

Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Lin Ming <ming.m.lin@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
diff --git a/drivers/acpi/executer/exstore.c b/drivers/acpi/executer/exstore.c
index 38b55e3..09e9684 100644
--- a/drivers/acpi/executer/exstore.c
+++ b/drivers/acpi/executer/exstore.c
@@ -403,7 +403,7 @@
 
 		ACPI_ERROR((AE_INFO, "Unknown Reference opcode %X",
 			    ref_desc->reference.opcode));
-		ACPI_DUMP_ENTRY(ref_desc, ACPI_LV_ERROR);
+		ACPI_DUMP_ENTRY(ref_desc, ACPI_LV_INFO);
 
 		status = AE_AML_INTERNAL;
 		break;