dt-bindings: xilinx: zynq: Improve boards description

Change the description of some boards to make it similar
to the value of the model property from their respective
device-tree, using the format "<manufacturer> <model>"
Signed-off-by: Luis Araneda <luaraneda@gmail.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>

Documentation/devicetree/bindings/arm/xilinx.txt

@@ -8,10 +8,10 @@ Required root node properties:
 
 Additional compatible strings:
 
-- Xilinx internal board cc108
+- Xilinx CC108 internal board
   "xlnx,zynq-cc108"
 
-- Xilinx internal board zc770 with different FMC cards
+- Xilinx ZC770 internal board, with different FMC cards
   "xlnx,zynq-zc770-xm010"
   "xlnx,zynq-zc770-xm011"
   "xlnx,zynq-zc770-xm012"