libc: add timerfd calls

(cherry-pick of 04c0ac14a49e0969333008a9522b64046d58fbdc.)

Change-Id: I06d0b6c2a8781602362b81f48faf1cca76b9ec05
diff --git a/libc/arch-arm/syscalls/timerfd_create.S b/libc/arch-arm/syscalls/timerfd_create.S
new file mode 100644
index 0000000..7e3f16f
--- /dev/null
+++ b/libc/arch-arm/syscalls/timerfd_create.S
@@ -0,0 +1,15 @@
+/* autogenerated by gensyscalls.py */
+#include <asm/unistd.h>
+#include <linux/err.h>
+#include <machine/asm.h>
+
+ENTRY(timerfd_create)
+    mov     ip, r7
+    ldr     r7, =__NR_timerfd_create
+    swi     #0
+    mov     r7, ip
+    cmn     r0, #(MAX_ERRNO + 1)
+    bxls    lr
+    neg     r0, r0
+    b       __set_errno
+END(timerfd_create)