pxa: move serial driver to drivers/serial

Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
diff --git a/include/configs/cerf250.h b/include/configs/cerf250.h
index 82d1401..b924758 100644
--- a/include/configs/cerf250.h
+++ b/include/configs/cerf250.h
@@ -60,6 +60,7 @@
 /*
  * select serial console configuration
  */
+#define CONFIG_PXA_SERIAL
 #define CONFIG_FFUART	     1	/* we use FFUART on CERF PXA */
 
 /* allow to overwrite serial and ethaddr */