dt-bindings: display: ssd1307fb: Add myself as binding co-maintainer

The ssd130x DRM driver also makes use of this Device Tree binding to allow
existing users of the fbdev driver to migrate without the need to change
their Device Trees.

Add myself as another maintainer of the binding, to make sure that I will
be on Cc when patches are proposed for it.

Suggested-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Acked-by: Rob Herring <robh@kernel.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Maxime Ripard <maxime@cerno.tech>
Link: https://patchwork.freedesktop.org/patch/msgid/20220214133935.3278933-1-javierm@redhat.com