staging: ozwpan: Change Maintainer

I will be not able to work on ozwpan driver anymore.
Remove my name & add Tateno as maintainer.

Signed-off-by: Rupesh Gujare <rupesh.gujare@atmel.com>
Acked-by: Shigekatsu Tateno <shigekatsu.tateno@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>