tty: i386/x86_64 arbitary speed support

Adds the needed TCGETS2/TCSETS2 ioctl calls, structures, defines and the like.
Tested against the test suite and passes.  Other platforms should need
roughly the same change.

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/asm-x86_64/termbits.h b/include/asm-x86_64/termbits.h
index 6cfc3bb10..7405756 100644
--- a/include/asm-x86_64/termbits.h
+++ b/include/asm-x86_64/termbits.h
@@ -160,7 +160,7 @@
 #define CMSPAR	  010000000000		/* mark or space (stick) parity */
 #define CRTSCTS	  020000000000		/* flow control */
 
-#define IBSHIFT	  8		/* Shift from CBAUD to CIBAUD */
+#define IBSHIFT	  16		/* Shift from CBAUD to CIBAUD */
 
 /* c_lflag bits */
 #define ISIG	0000001