[PATCH] um: Document dtb command line option

[Vincent Whitchurch]

On Tue, Jan 04, 2022 at 11:44:57AM +0100, anton.ivanov at cambridgegreys.com wrote:
> From: Anton Ivanov <anton.ivanov at cambridgegreys.com>
> 
> Add documentation for the dtb command line option and the
> ability to load/parse device trees.
> 
> Signed-off-by: Anton Ivanov <anton.ivanov at cambridgegreys.com>

LGTM, thanks.

Reviewed-by: Vincent Whitchurch <vincent.whitchurch at axis.com>