arch/x86: Replace some __SMM__ guards

We generally do not guard source in attempts to reduce
the final object sizes, but rely on garbage collection.

Most of the __unused attributes inserted here will be
removed when remaining __SIMPLE_DEVICE__ guards can
be removed.

Change-Id: I2440931fab4f41d7e8249c082e6c9b5a9cd0ef13
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/36641
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
diff --git a/src/southbridge/intel/lynxpoint/usb_xhci.c b/src/southbridge/intel/lynxpoint/usb_xhci.c
index 686e06a..4818d62 100644
--- a/src/southbridge/intel/lynxpoint/usb_xhci.c
+++ b/src/southbridge/intel/lynxpoint/usb_xhci.c
@@ -166,7 +166,7 @@
 		usb_xhci_reset_status_usb3(mem_base, port);
 }
 
-#ifdef __SMM__
+#ifdef __SIMPLE_DEVICE__
 
 /* Handler for XHCI controller on entry to S3/S4/S5 */
 void usb_xhci_sleep_prepare(pci_devfn_t dev, u8 slp_typ)
@@ -251,7 +251,7 @@
 	usb_xhci_reset_usb3(PCH_XHCI_DEV, 1);
 }
 
-#else /* !__SMM__ */
+#else /* !__SIMPLE_DEVICE__ */
 
 static void usb_xhci_clock_gating(struct device *dev)
 {
@@ -395,4 +395,4 @@
 	.vendor	 = PCI_VENDOR_ID_INTEL,
 	.devices = pci_device_ids,
 };
-#endif /* !__SMM__ */
+#endif /* !__SIMPLE_DEVICE__ */