Merge tag 'zynq-dt-for-3.19' of https://github.com/Xilinx/linux-xlnx into next/dt

Pull "arm: Xilinx Zynq dt patches for v3.19" from Michal Simek:

- Declare Digilent and vendor
- Add Zybo board support
- Fix VDMA documentation to be align with the driver

* tag 'zynq-dt-for-3.19' of https://github.com/Xilinx/linux-xlnx

:
  arm: dts: zynq: Add Digilent ZYBO board
  arm: dts: zynq: Move crystal freq. to board level
  doc: dt: vendor-prefixes: Add Digilent Inc
  Documentation: devicetree: Fix Xilinx VDMA specification

Signed-off-by: Arnd Bergmann <arnd@arndb.de>