Update to v4.15 kernel headers.

Test: Compiles, boots bullhead/hikey960.
Change-Id: I118beb8b6cac0881b1270f9bf6981959297a41a8
diff --git a/libc/kernel/uapi/linux/nfc.h b/libc/kernel/uapi/linux/nfc.h
index e212b31..72e3520 100644
--- a/libc/kernel/uapi/linux/nfc.h
+++ b/libc/kernel/uapi/linux/nfc.h
@@ -54,6 +54,7 @@
   NFC_CMD_SE_IO,
   NFC_CMD_ACTIVATE_TARGET,
   NFC_CMD_VENDOR,
+  NFC_CMD_DEACTIVATE_TARGET,
   __NFC_CMD_AFTER_LAST
 };
 #define NFC_CMD_MAX (__NFC_CMD_AFTER_LAST - 1)