Documentation/vboot: Drop deprecated options from example

4K keys are now default.

Change-Id: I16599d0e8b874f9e8a56100fea06d6e4f94a5c00
Signed-off-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/37149
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>

Documentation/security/vboot/index.md

@@ -231,7 +231,7 @@ More details are available in `3rdparty/vboot/README`.
 #  The keys were made using the following command
 #
 #        3rdparty/vboot/scripts/keygeneration/create_new_keys.sh  \
-#                --4k --4k-root --output $PWD/keys
+#                --output $PWD/keys
 #
 #
 #  The "magic" numbers below are derived from the GBB section in