pxa: move serial driver to drivers/serial

Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
diff --git a/include/configs/xsengine.h b/include/configs/xsengine.h
index 7e2abbf..2697cca 100644
--- a/include/configs/xsengine.h
+++ b/include/configs/xsengine.h
@@ -99,6 +99,7 @@
 #define CONFIG_SMC_USE_32_BIT		1
 
 /* select serial console configuration */
+#define CONFIG_PXA_SERIAL
 #define CONFIG_FFUART			1
 
 /* allow to overwrite serial and ethaddr */