console: Add write line routine

Add write line routine which is called indirectly by FSP.

TEST=Build and run on Galileo Gen2.

Change-Id: Idefb6e9ebe5a2b614055dabddc1882bfa3bba673
Signed-off-by: Lee Leahy <leroy.p.leahy@intel.com>
Reviewed-on: https://review.coreboot.org/16127
Tested-by: build bot (Jenkins)
Reviewed-by: Martin Roth <martinroth@google.com>

src/include/console/streams.h

@@ -14,10 +14,19 @@
 #ifndef _CONSOLE_STREAMS_H_
 #define _CONSOLE_STREAMS_H_
 
+#include <stddef.h>
+#include <stdint.h>
+
 void console_hw_init(void);
 void console_tx_byte(unsigned char byte);
 void console_tx_flush(void);
 
+/*
+ * Write number_of_bytes data bytes from buffer to the serial device.
+ * If number_of_bytes is zero, wait until all serial data is output.
+ */
+void console_write_line(uint8_t *buffer, size_t number_of_bytes);
+
 /* For remote GDB debugging. */
 void gdb_hw_init(void);
 void gdb_tx_byte(unsigned char byte);