soc/intel/cannonlake: Get rid of device_t

Use of device_t has been abandoned in ramstage.

Change-Id: Iea56a6560bb23d48d19211304e57fc08e1c27fd6
Signed-off-by: Elyes HAOUAS <ehaouas@noos.fr>
Reviewed-on: https://review.coreboot.org/26584
Reviewed-by: Nico Huber <nico.h@gmx.de>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/soc/intel/cannonlake/pmc.c

@@ -137,7 +137,7 @@ static void pch_power_options(struct device *dev)
 
 static void pmc_init(void *unused)
 {
-	device_t dev = PCH_DEV_PMC;
+	struct device *dev = PCH_DEV_PMC;
 	config_t *config = dev->chip_info;
 
 	rtc_init();