MAINTAINERS: pps: Update pps-gpio bindings location

MAINTAINERS: pps: Update pps-gpio bindings location

The pps-gpio bindings have been converted to yaml.

Update the file path accordingly.

Fixes: 7ceb60ece856 ("dt-bindings: pps: pps-gpio: Convert to yaml")
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202308230517.n0rrszYH-lkp@intel.com/
Signed-off-by: Fabio Estevam <festevam@denx.de>
Acked-by: Rodolfo Giometti <giometti@enneenne.com>
Link: https://lore.kernel.org/r/20230822213317.60798-1-festevam@gmail.com
Signed-off-by: Rob Herring <robh@kernel.org>