video: Move sm501fb devicetree binding documentation to a better place.

Now that there is a Documentation/devicetree hierarchy, and the driver in
question has no specific platform dependency, move the binding
information to a more appropriate place.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>

diff --git a/Documentation/powerpc/dts-bindings/sm501.txt b/Documentation/devicetree/bindings/fb/sm501fb.txt
similarity index 100%
rename from Documentation/powerpc/dts-bindings/sm501.txt
rename to Documentation/devicetree/bindings/fb/sm501fb.txt