pxa: move serial driver to drivers/serial

Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>

include/configs/xm250.h

diff --git a/include/configs/xm250.h b/include/configs/xm250.h
index c8bdf31..f18701a 100644
--- a/include/configs/xm250.h
+++ b/include/configs/xm250.h
@@ -77,6 +77,7 @@
 /*
  * select serial console configuration
  */
+#define CONFIG_PXA_SERIAL
 #define CONFIG_FFUART	       1       /* we use FFUART */
 
 /* allow to overwrite serial and ethaddr */