Update cf_adv7511_zed design

* Sync ps7_system_prj.xml with the one from zedboard.org
* Set IO standard for the 3.3V bank to LVCMOS33
* Connect LEDs, switches and buttons to the PS7 gpio controller
* Fixed MIO setup (Thanks to Mike Looijmans)
* Upgrade processing_system7 to 4.02.a, upgrade vdma to 5.04.a

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>