Update to v5.12 kernel headers.

Kernel headers coming from:

Git: https://android.googlesource.com/kernel/common/
Branch: android-mainline
Tag: android-mainline-5.12

Test: Boots flame device and runs bionic unit tests.
Test: Boots acloud device and runs bionic unit tests.

Change-Id: I8ac107ce9d4978be3ef9517b90ad6ecafd06785a
diff --git a/libc/kernel/uapi/linux/openat2.h b/libc/kernel/uapi/linux/openat2.h
index 27136af..d397a00 100644
--- a/libc/kernel/uapi/linux/openat2.h
+++ b/libc/kernel/uapi/linux/openat2.h
@@ -29,4 +29,5 @@
 #define RESOLVE_NO_SYMLINKS 0x04
 #define RESOLVE_BENEATH 0x08
 #define RESOLVE_IN_ROOT 0x10
+#define RESOLVE_CACHED 0x20
 #endif