Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/drivers/hwtracing/intel_th/sth.c b/drivers/hwtracing/intel_th/sth.c
index 4b7ae47..3a1f4e6 100644
--- a/drivers/hwtracing/intel_th/sth.c
+++ b/drivers/hwtracing/intel_th/sth.c
@@ -84,8 +84,12 @@
 	/* Global packets (GERR, XSYNC, TRIG) are sent with register writes */
 	case STP_PACKET_GERR:
 		reg += 4;
+		/* fall through */
+
 	case STP_PACKET_XSYNC:
 		reg += 8;
+		/* fall through */
+
 	case STP_PACKET_TRIG:
 		if (flags & STP_PACKET_TIMESTAMPED)
 			reg += 4;