arm720t/clps7111: move serial driver to drivers/serial

add CONFIG_CLPS7111_SERIAL to activate the driver

Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
diff --git a/include/configs/impa7.h b/include/configs/impa7.h
index efd4214..c7001cc 100644
--- a/include/configs/impa7.h
+++ b/include/configs/impa7.h
@@ -54,6 +54,7 @@
 /*
  * select serial console configuration
  */
+#define CONFIG_CLPS7111_SERIAL
 #define CONFIG_SERIAL1		1	/* we use Serial line 1 */
 
 /* allow to overwrite serial and ethaddr */