cmake: Add install target for documentation

The documentation is being built with doxygen if WITH_DOCUMENTATION is set
to ON, but the install target is missing. Thus in a build framework like
yocto, the documentation files must be installed manuelly into the
correct location.

This change adds the missing install target with the common default
destination CMAKE_INSTALL_DOCDIR from GNUInstallDirs.
CMAKE_INSTALL_DOCDIR == ${CMAKE_INSTALL_DATAROOTDIR}/doc/${PROJECT_NAME}

Change-Id: Idaa558a567395d091ab9c0f2b6defe6f36933a46

0 files changed, 0 insertions, 0 deletions