pl011: allow alternate stdout to be used

Till now only pl011 UART is available stdout but there is a usecase to
redirect it to other channel.

This patch decouples console_putc implementation from pl011.

Signed-off-by: Manish Pandey <manish.pandey2@arm.com>
Change-Id: I38e8c5c90421fad2425228f407e6f29bdf6b08c7
diff --git a/include/drivers/arm/pl011.h b/include/drivers/arm/pl011.h
index cba325d..3e19ee8 100644
--- a/include/drivers/arm/pl011.h
+++ b/include/drivers/arm/pl011.h
@@ -75,4 +75,13 @@
 /* Constants */
 #define PL011_BAUDRATE		115200
 
+#ifndef __ASSEMBLER__
+#include <stdint.h>
+
+/* Functions */
+
+int console_pl011_putc(int);
+
+#endif /* __ASSEMBLER__ */
+
 #endif	/* __PL011_H__ */