dt-bindings: display: ssd1307fb: Add vendor prefix to width and height

The commit 591825fb ("dt-bindings: display: ssd1307fb: Remove default
width and height values") used the wrong properties for width and height,
instead of the correct "solomon,width" and "solomon,height" properties.

Fix this by adding the vendor prefix to the width and height properties.

Fixes: 591825fb

 ("dt-bindings: display: ssd1307fb: Remove default width and height values")
Reported-by: Conor Dooley <conor@kernel.org>
Closes: https://lore.kernel.org/dri-devel/20231218-example-envision-b41ca8efa251@spud/
Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Acked-by: Rob Herring <robh@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20231229112026.2797483-2-javierm@redhat.com