kernel: fix boot.consoleLogLevel description

The current description describes the opposite influence of the setting
https://www.kernel.org/doc/Documentation/admin-guide/kernel-parameters.txt

(cherry picked from commit 9f7eabc)

nixos/modules/system/boot/kernel.nix

@@ -77,8 +77,8 @@ in
       type = types.int;
       default = 4;
       description = ''
-        The kernel console log level.  Log messages with a priority
-        numerically less than this will not appear on the console.
+        The kernel console <literal>loglevel</literal>. All Kernel Messages with a log level smaller
+        than this setting will be printed to the console.
       '';
     };