Install as arch-independent (#309)

xternsor-python is header only library, so prefer arch-independed paths
cmake.

References:
*
xtensor-stack/xtl@d877d94
*
xtensor-stack/xtensor@7738389

Co-authored-by: Johan Mabille <johan.mabille@gmail.com>

Author: matwey

CMakeLists.txt

@@ -124,13 +124,14 @@ export(EXPORT ${PROJECT_NAME}-targets
 install(FILES ${XTENSOR_PYTHON_HEADERS}
         DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}/xtensor-python)
 
+
 configure_file(${PROJECT_NAME}.pc.in
                "${CMAKE_CURRENT_BINARY_DIR}/${PROJECT_NAME}.pc"
                 @ONLY)
 install(FILES "${CMAKE_CURRENT_BINARY_DIR}/${PROJECT_NAME}.pc"
         DESTINATION "${CMAKE_INSTALL_DATADIR}/pkgconfig/")
 
-set(XTENSOR_PYTHON_CMAKECONFIG_INSTALL_DIR "${CMAKE_INSTALL_LIBDIR}/cmake/${PROJECT_NAME}" CACHE
+set(XTENSOR_PYTHON_CMAKECONFIG_INSTALL_DIR "${CMAKE_INSTALL_DATADIR}/cmake/${PROJECT_NAME}" CACHE
     STRING "install path for xtensor-pythonConfig.cmake")
 
 configure_package_config_file(${PROJECT_NAME}Config.cmake.in