Move console definitions into a new console.h file

The console includes a global variable and several functions that are only
used by a small subset of U-Boot files. Before adding more functions, move
the definitions into their own header file.

Signed-off-by: Simon Glass <sjg@chromium.org>

drivers/fpga/zynqpl.c

@@ -8,6 +8,7 @@
  */
 
 #include <common.h>
+#include <console.h>
 #include <asm/io.h>
 #include <fs.h>
 #include <zynqpl.h>