platform/x86: intel-vbtn: reduce unnecessary messages for normal users

Unsupported events is only useful for developers and does not meaningful
for users. Using dev_dbg makes more sense and reduces noise in kernel
messages.
Signed-off-by: Alex Hung <alex.hung@canonical.com>
Signed-off-by: Darren Hart (VMware) <dvhart@infradead.org>

drivers/platform/x86/intel-vbtn.c

@@ -83,7 +83,7 @@ static void notify_handler(acpi_handle handle, u32 event, void *context)
 	} else if (sparse_keymap_report_event(priv->input_dev, event, 1, true)) {
 		return;
 	}
-	dev_info(&device->dev, "unknown event index 0x%x\n", event);
+	dev_dbg(&device->dev, "unknown event index 0x%x\n", event);
 }
 
 static int intel_vbtn_probe(struct platform_device *device)