Update to v6.8 kernel headers.

Kernel headers coming from:

Git: https://android.googlesource.com/kernel/common/
Branch: android-mainline
Tag: android-mainline-6.8

Test: Builds and bionic unit tests pass on raven.
Test: Able to log in to an Android GO 32 bit device.
Change-Id: I0022cdb20c19726f526acaab2866f1e25794b77e
diff --git a/libc/kernel/uapi/linux/version.h b/libc/kernel/uapi/linux/version.h
index 645a2ab..549c079 100644
--- a/libc/kernel/uapi/linux/version.h
+++ b/libc/kernel/uapi/linux/version.h
@@ -4,8 +4,8 @@
  * See https://android.googlesource.com/platform/bionic/+/master/libc/kernel/
  * for more information.
  */
-#define LINUX_VERSION_CODE 395008
+#define LINUX_VERSION_CODE 395264
 #define KERNEL_VERSION(a,b,c) (((a) << 16) + ((b) << 8) + ((c) > 255 ? 255 : (c)))
 #define LINUX_VERSION_MAJOR 6
-#define LINUX_VERSION_PATCHLEVEL 7
+#define LINUX_VERSION_PATCHLEVEL 8
 #define LINUX_VERSION_SUBLEVEL 0