arch/riscv/include/arch: Don't use device_t

Use of device_t is deprecated.

Change-Id: If52de0d87b02419090b29a7cf1952905d3f975f6
Signed-off-by: Elyes HAOUAS <ehaouas@noos.fr>
Reviewed-on: https://review.coreboot.org/28691
Reviewed-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/arch/riscv/include/arch/cpu.h

@@ -31,7 +31,7 @@ struct cpu_driver {
 struct thread;
 
 struct cpu_info {
-	device_t cpu;
+	struct device *cpu;
 	unsigned long index;
 #if IS_ENABLED(CONFIG_COOP_MULTITASKING)
 	struct thread *thread;