This way clients can use wayland-scanner to generate their client
headers, and do not need to copy manually the extension.
Also, generate a pkgconfig file otherwise clients will have a hard time
finding the proper pkgdatadir path in order to get the agl-shell xml
file.
Bug-AGL: SPEC-3167
Signed-off-by: Marius Vlad <marius.vlad@collabora.com>
Change-Id: Id62e49b57c8864e0bdb695c03198eac782efcbeb