mb/winnet: Get rid of device_t

Use of device_t has been abandoned in ramstage.

Change-Id: Ie6a8364bdd272515e1567061ae0b117392c268aa
Signed-off-by: Elyes HAOUAS <ehaouas@noos.fr>
Reviewed-on: https://review.coreboot.org/26092
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Werner Zeh <werner.zeh@siemens.com>

src/mainboard/winnet/g170/mainboard.c

@@ -24,7 +24,7 @@ static void mainboard_final(void *chip_info)
 {
 	                                       /*  A  B   C  D */
 	static const unsigned char irq_map[4] = { 11, 5, 10, 0 };
-	device_t lpc_dev;
+	struct device *lpc_dev;
 
 	printk(BIOS_INFO, "Setting up G170 IRQ routing...\n");