ARM: tegra: document which Dalmore revisions are supported

There are a number of revisions of the Dalmore board, each with a variety
of incompatible SW-visible HW changes. The Dalmore DT file in the kernel
only supports HW revision A04. Document this in the DT file.
Reported-by: Paul Walmsley <pwalmsley@nvidia.com>
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Reviewed-by: Thierry Reding <treding@nvidia.com>

arch/arm/boot/dts/tegra114-dalmore.dts

+/*
+ * This dts file supports Dalmore A04.
+ * Other board revisions are not supported
+ */
+
 /dts-v1/;
 
 #include <dt-bindings/input/input.h>