Documentation: Add nospectre_v1 parameter

BugLink: https://bugs.launchpad.net/bugs/1830176

commit 26cb1f36 upstream.

Currently only supported on powerpc.
Signed-off-by: Diana Craciun <diana.craciun@nxp.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[juergh: Adjusted context.]
Signed-off-by: Juerg Haefliger <juergh@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>

Documentation/kernel-parameters.txt

@@ -2606,6 +2606,10 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
 			nosmt=force: Force disable SMT, cannot be undone
 				     via the sysfs control file.
 
+	nospectre_v1	[PPC] Disable mitigations for Spectre Variant 1 (bounds
+			check bypass). With this option data leaks are possible
+			in the system.
+
 	nospectre_v2	[X86,PPC_FSL_BOOK3E] Disable all mitigations for the Spectre variant 2
 			(indirect branch prediction) vulnerability. System may
 			allow data leaks with this option, which is equivalent