x86: Move i8254_init() to x86_cpu_init_f()

Right now i8254_init() is called from timer_init() in the tsc timer
driver. But actually i8254 and tsc are completely different things.
Since tsc timer has been converted to driver model, we should find
a new place that is appropriate for U-Boot to call i8254_init(),
which is now x86_cpu_init_f().

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Acked-by: Simon Glass <sjg@chromium.org>
diff --git a/arch/x86/cpu/cpu.c b/arch/x86/cpu/cpu.c
index 1707993..381d835 100644
--- a/arch/x86/cpu/cpu.c
+++ b/arch/x86/cpu/cpu.c
@@ -399,6 +399,11 @@
 		}
 	}
 
+#ifdef CONFIG_I8254_TIMER
+	/* Set up the i8254 timer if required */
+	i8254_init();
+#endif
+
 	return 0;
 }