Add _addr_lsb field to ia64 siginfo

The huge pages code uses the siginfo _addr_lsb field, but ia64
was missing it. Add it to ia64 too (over some padding) to avoid
compilation failures.
Acked-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>

arch/ia64/include/asm/siginfo.h

@@ -62,6 +62,7 @@ typedef struct siginfo {
 			int _imm;		/* immediate value for "break" */
 			unsigned int _flags;	/* see below */
 			unsigned long _isr;	/* isr */
+			short _addr_lsb;	/* lsb of faulting address */
 		} _sigfault;
 
 		/* SIGPOLL */