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/linux/ppp-ioctl.h b/libc/kernel/uapi/linux/ppp-ioctl.h
index f188dff..69c6e6d 100644
--- a/libc/kernel/uapi/linux/ppp-ioctl.h
+++ b/libc/kernel/uapi/linux/ppp-ioctl.h
@@ -105,6 +105,8 @@
 #define PPPIOCATTCHAN _IOW('t', 56, int)
 #define PPPIOCGCHAN _IOR('t', 55, int)
 #define PPPIOCGL2TPSTATS _IOR('t', 54, struct pppol2tp_ioc_stats)
+#define PPPIOCBRIDGECHAN _IOW('t', 53, int)
+#define PPPIOCUNBRIDGECHAN _IO('t', 52)
 #define SIOCGPPPSTATS (SIOCDEVPRIVATE + 0)
 #define SIOCGPPPVER (SIOCDEVPRIVATE + 1)
 #define SIOCGPPPCSTATS (SIOCDEVPRIVATE + 2)