Update kernel headers and add syscall "perf_event_open"

Change-Id: I43f12b727881df002a8524f2738586c043833bae
diff --git a/libc/SYSCALLS.TXT b/libc/SYSCALLS.TXT
index b9bd9e7..14b990d 100644
--- a/libc/SYSCALLS.TXT
+++ b/libc/SYSCALLS.TXT
@@ -264,6 +264,7 @@
 int     klogctl:syslog(int, char *, int)   103
 int     sysinfo(struct sysinfo *)  116
 int     personality(unsigned long)  136
+long    perf_event_open(struct perf_event_attr *attr_uptr, pid_t pid, int cpu, int group_fd, unsigned long flags) 364
 
 # futex
 int	futex(void *, int, int, void *, void *, int) 240