fix xtensa timerfd breakage

In file included from /home/bunk/linux/kernel-2.6/git/linux-2.6/arch/xtensa/kernel/syscall.c:39:
include2/asm/unistd.h:681: error: 'sys_timerfd' undeclared here (not in a function)
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Cc: Christian Zankel <chris@zankel.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

include/asm-xtensa/unistd.h

@@ -677,8 +677,8 @@ __SYSCALL(303, sys_ni_syscall, 0)
 
 #define __NR_signalfd				304
 __SYSCALL(304, sys_signalfd, 3)
-#define __NR_timerfd				305
-__SYSCALL(305, sys_timerfd, 4)
+/*  305 was __NR_timerfd  */
+__SYSCALL(305, sys_ni_syscall, 0)
 #define __NR_eventfd				306
 __SYSCALL(306, sys_eventfd, 1)