of: consolidate linker section OF match table declarations

We now have several OF match tables using linker sections that are
nearly the same definition. The only variation is the callback function
prototype. Create a common define for creating linker section OF match
table entries which each table declaration can use.

Acked-by: Grant Likely <grant.likely@linaro.org>
Signed-off-by: Rob Herring <robh@kernel.org>