Improves the use of GNUInstallDirs for yocto
Improves the use of GNUInstallDirs for yocto

The previous implementation was not fully compliant with
standards. It was missing some of the predefined variable
DATAROOTDIR, it was missing specificity of
CMAKE_INSTALL_FULL_SYSCONFDIR.

It also was not compatible with yocto build.

Change-Id: I6a057786c205e7f2106c12afd5de191c18f372d9
Signed-off-by: José Bollo <08496fd66cc394b517cafa0b18bcb9ce79fe4230@iot.bzh>

Samsung/cynara,Samsung/cynara,Samsung/cynara