Update to v4.17.3 kernel headers.

Test: Builds, boots on a walleye.
Change-Id: I389d8b61ec00ea309e38d1b1a2e0dace48c21edb
diff --git a/libc/kernel/uapi/linux/dvb/frontend.h b/libc/kernel/uapi/linux/dvb/frontend.h
index c8a48c1..d060138 100644
--- a/libc/kernel/uapi/linux/dvb/frontend.h
+++ b/libc/kernel/uapi/linux/dvb/frontend.h
@@ -247,7 +247,8 @@
 #define DTV_STAT_POST_TOTAL_BIT_COUNT 67
 #define DTV_STAT_ERROR_BLOCK_COUNT 68
 #define DTV_STAT_TOTAL_BLOCK_COUNT 69
-#define DTV_MAX_COMMAND DTV_STAT_TOTAL_BLOCK_COUNT
+#define DTV_SCRAMBLING_SEQUENCE_INDEX 70
+#define DTV_MAX_COMMAND DTV_SCRAMBLING_SEQUENCE_INDEX
 enum fe_pilot {
   PILOT_ON,
   PILOT_OFF,