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/kernel/uapi/asm-generic/unistd.h b/libc/kernel/uapi/asm-generic/unistd.h
index 412e751..f284254 100644
--- a/libc/kernel/uapi/asm-generic/unistd.h
+++ b/libc/kernel/uapi/asm-generic/unistd.h
@@ -401,8 +401,9 @@
 #define __NR_pidfd_getfd 438
 #define __NR_faccessat2 439
 #define __NR_process_madvise 440
+#define __NR_epoll_pwait2 441
 #undef __NR_syscalls
-#define __NR_syscalls 441
+#define __NR_syscalls 442
 #if __BITS_PER_LONG == 64 && !defined(__SYSCALL_COMPAT)
 #define __NR_fcntl __NR3264_fcntl
 #define __NR_statfs __NR3264_statfs