ima: Reword IMA_KEYRINGS_PERMIT_SIGNED_BY_BUILTIN_OR_SECONDARY

When the machine keyring is enabled, it may be used as a trust source
for the .ima keyring.  Add a reference to this in
IMA_KEYRINGS_PERMIT_SIGNED_BY_BUILTIN_OR_SECONDARY.
Signed-off-by: Eric Snowberg <eric.snowberg@oracle.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>

security/integrity/ima/Kconfig

@@ -243,7 +243,7 @@ config IMA_APPRAISE_MODSIG
 	   to accept such signatures.
 
 config IMA_KEYRINGS_PERMIT_SIGNED_BY_BUILTIN_OR_SECONDARY
-	bool "Permit keys validly signed by a built-in or secondary CA cert (EXPERIMENTAL)"
+	bool "Permit keys validly signed by a built-in, machine (if configured) or secondary (EXPERIMENTAL)"
 	depends on SYSTEM_TRUSTED_KEYRING
 	depends on SECONDARY_TRUSTED_KEYRING
 	depends on INTEGRITY_ASYMMETRIC_KEYS
@@ -251,14 +251,14 @@ config IMA_KEYRINGS_PERMIT_SIGNED_BY_BUILTIN_OR_SECONDARY
 	default n
 	help
 	  Keys may be added to the IMA or IMA blacklist keyrings, if the
-	  key is validly signed by a CA cert in the system built-in or
-	  secondary trusted keyrings. The key must also have the
-	  digitalSignature usage set.
+	  key is validly signed by a CA cert in the system built-in,
+	  machine (if configured), or secondary trusted keyrings. The
+	  key must also have the digitalSignature usage set.
 
 	  Intermediate keys between those the kernel has compiled in and the
 	  IMA keys to be added may be added to the system secondary keyring,
 	  provided they are validly signed by a key already resident in the
-	  built-in or secondary trusted keyrings.
+	  built-in, machine (if configured) or secondary trusted keyrings.
 
 config IMA_BLACKLIST_KEYRING
 	bool "Create IMA machine owner blacklist keyrings (EXPERIMENTAL)"