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/nfs3.h b/libc/kernel/uapi/linux/nfs3.h
index 3972d0b..af0d668 100644
--- a/libc/kernel/uapi/linux/nfs3.h
+++ b/libc/kernel/uapi/linux/nfs3.h
@@ -67,6 +67,11 @@
   NF3FIFO = 7,
   NF3BAD = 8
 };
+enum nfs3_time_how {
+  DONT_CHANGE = 0,
+  SET_TO_SERVER_TIME = 1,
+  SET_TO_CLIENT_TIME = 2,
+};
 struct nfs3_fh {
   unsigned short size;
   unsigned char data[NFS3_FHSIZE];