openamp: update install for updated OpenAMP demos
openamp: update install for updated OpenAMP demos

The OpenAMP code base has updated the demos, the recipe needs update
to install the new OpenAMP demos.

Signed-off-by: Wendy Liang <cac46fad14f88489ab4dbc3c1082c7dafae20187@xilinx.com>

OpenAMP/meta-openamp,OpenAMP/meta-openamp