gpio: zynq: remove unneeded (void *) casts in of_match_table

of_device_id::data is an opaque pointer.  No explicit cast is needed.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Sören Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>