ima: Remove EXPERIMENTAL from Kconfig

Remove the EXPERIMENTAL from the
IMA_KEYRINGS_PERMIT_SIGNED_BY_BUILTIN_OR_SECONDARY Kconfig
now that digitalSignature usage enforcement is set.
Signed-off-by: Eric Snowberg <eric.snowberg@oracle.com>
link: https://lore.kernel.org/all/20230508220708.2888510-4-eric.snowberg@oracle.com/Acked-by: Jarkko Sakkinen <jarkko@kernel.org>
Reviewed-by: Mimi Zohar <zohar@linux.ibm.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, machine (if configured) or secondary (EXPERIMENTAL)"
+	bool "Permit keys validly signed by a built-in, machine (if configured) or secondary"
 	depends on SYSTEM_TRUSTED_KEYRING
 	depends on SECONDARY_TRUSTED_KEYRING
 	depends on INTEGRITY_ASYMMETRIC_KEYS