Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/include/linux/hw_random.h b/include/linux/hw_random.h
index bee0827..8e6dd90 100644
--- a/include/linux/hw_random.h
+++ b/include/linux/hw_random.h
@@ -1,7 +1,7 @@
 /*
 	Hardware Random Number Generator
 
-	Please read Documentation/hw_random.txt for details on use.
+	Please read Documentation/admin-guide/hw_random.rst for details on use.
 
 	----------------------------------------------------------
 	This software may be used and distributed according to the terms
@@ -33,7 +33,8 @@
  *			and max is a multiple of 4 and >= 32 bytes.
  * @priv:		Private data, for use by the RNG driver.
  * @quality:		Estimation of true entropy in RNG's bitstream
- *			(per mill).
+ *			(in bits of entropy per 1024 bits of input;
+ *			valid values: 1 to 1024, or 0 for unknown).
  */
 struct hwrng {
 	const char *name;