media: dt-bindings: media: max9286: Re-indent example

The dt-bindings examples are usually indented with 4 spaces.

The maxim,max9286 schema has the example indented with only
2 spaces, re-indent it.

Cosmetic change only.
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>