x86: quark: Use reset_cpu()

Now that reset_cpu() functions correctly, use it instead of directly
accessing the port.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Tested-by: Bin Meng <bmeng.cn@gmail.com>

arch/x86/cpu/quark/quark.c

@@ -122,7 +122,7 @@ int print_cpuinfo(void)
 void reset_cpu(ulong addr)
 {
 	/* cold reset */
-	outb(0x08, PORT_RESET);
+	x86_full_reset();
 }
 
 int cpu_mmc_init(bd_t *bis)