Allow console input to be disabled

Added new CONFIG_DISABLE_CONSOLE define and GD_FLG_DISABLE_CONSOLE.

When CONFIG_DISABLE_CONSOLE is defined, setting
GD_FLG_DISABLE_CONSOLE disables all console input and output.

Signed-off-by: Mark Jackson <mpfj@mimc.co.uk>
diff --git a/include/asm-blackfin/global_data.h b/include/asm-blackfin/global_data.h
index b0b01e4..2f40870 100644
--- a/include/asm-blackfin/global_data.h
+++ b/include/asm-blackfin/global_data.h
@@ -64,6 +64,7 @@
 #define	GD_FLG_POSTFAIL	0x00008	/* Critical POST test failed     */
 #define	GD_FLG_POSTSTOP	0x00010	/* POST seqeunce aborted	 */
 #define	GD_FLG_LOGINIT	0x00020	/* Log Buf has been initialized	 */
+#define GD_FLG_DISABLE_CONSOLE	0x00040		/* Disable console (in & out)	 */
 
 #define DECLARE_GLOBAL_DATA_PTR     register gd_t * volatile gd asm ("P5")