Merge back earlier 'acpi-lpss' material for v3.20

drivers/acpi/acpi_lpss.c

@@ -125,7 +125,7 @@ static struct lpss_device_desc lpt_dev_desc = {
 };
 
 static struct lpss_device_desc lpt_i2c_dev_desc = {
-	.flags = LPSS_CLK | LPSS_CLK_GATE | LPSS_LTR,
+	.flags = LPSS_CLK | LPSS_LTR,
 	.prv_offset = 0x800,
 };
 
@@ -334,6 +334,8 @@ static int acpi_lpss_create_device(struct acpi_device *adev,
 				pdata->mmio_size = resource_size(&rentry->res);
 			pdata->mmio_base = ioremap(rentry->res.start,
 						   pdata->mmio_size);
+			if (!pdata->mmio_base)
+				goto err_out;
 			break;
 		}