Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/include/uapi/linux/serial.h b/include/uapi/linux/serial.h
index 3fdd0de..93eb3c4 100644
--- a/include/uapi/linux/serial.h
+++ b/include/uapi/linux/serial.h
@@ -132,4 +132,21 @@
 					   are a royal PITA .. */
 };
 
+/*
+ * Serial interface for controlling ISO7816 settings on chips with suitable
+ * support. Set with TIOCSISO7816 and get with TIOCGISO7816 if supported by
+ * your platform.
+ */
+struct serial_iso7816 {
+	__u32	flags;			/* ISO7816 feature flags */
+#define SER_ISO7816_ENABLED		(1 << 0)
+#define SER_ISO7816_T_PARAM		(0x0f << 4)
+#define SER_ISO7816_T(t)		(((t) & 0x0f) << 4)
+	__u32	tg;
+	__u32	sc_fi;
+	__u32	sc_di;
+	__u32	clk;
+	__u32	reserved[5];
+};
+
 #endif /* _UAPI_LINUX_SERIAL_H */