northbridge/intel/sandybridge: transition away from device_t

Replace the use of the old device_t definition inside
northbridge/intel/sandybridge.

The patch has been tested both with the arch/io.h definition of device_t
enabled and disabled in order to ensure compatibility while the
transaction takes place.

Change-Id: I35cc76ec7b6baa216666d06f6f325f43ac69067e
Signed-off-by: Antonello Dettori <dev@dettori.io>
Reviewed-on: https://review.coreboot.org/16409
Tested-by: build bot (Jenkins)
Reviewed-by: Martin Roth <martinroth@google.com>

src/northbridge/intel/sandybridge/sandybridge.h

@@ -234,7 +234,7 @@ void mainboard_config_superio(void);
 int mainboard_should_reset_usb(int s3resume);
 void perform_raminit(int s3resume);
 
-#if ENV_RAMSTAGE
+#if ENV_RAMSTAGE && !defined(__SIMPLE_DEVICE__)
 #include <device/device.h>
 
 struct acpi_rsdp;