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-x86/asm/unistd_64.h b/libc/kernel/uapi/asm-x86/asm/unistd_64.h
index 04932fc..82268bd 100644
--- a/libc/kernel/uapi/asm-x86/asm/unistd_64.h
+++ b/libc/kernel/uapi/asm-x86/asm/unistd_64.h
@@ -370,4 +370,5 @@
 #define __NR_pidfd_getfd 438
 #define __NR_faccessat2 439
 #define __NR_process_madvise 440
+#define __NR_epoll_pwait2 441
 #endif