Update to v5.11 kernel headers.

Kernel headers coming from:

Git: https://android.googlesource.com/kernel/common/
Branch: android-mainline
Tag: android-mainline-5.11

Test: Built cuttlefish and flame images. Ran bionic unit tests on both.
Change-Id: Ie60337aafad4bda55af99b6c8fe9f56bf2fa787f
diff --git a/libc/include/bits/glibc-syscalls.h b/libc/include/bits/glibc-syscalls.h
index cc7645b..6b00f11 100644
--- a/libc/include/bits/glibc-syscalls.h
+++ b/libc/include/bits/glibc-syscalls.h
@@ -162,6 +162,9 @@
 #if defined(__NR_epoll_pwait)
   #define SYS_epoll_pwait __NR_epoll_pwait
 #endif
+#if defined(__NR_epoll_pwait2)
+  #define SYS_epoll_pwait2 __NR_epoll_pwait2
+#endif
 #if defined(__NR_epoll_wait)
   #define SYS_epoll_wait __NR_epoll_wait
 #endif