Update FindGlog.cmake to create glog::glog target

This change to FindGlog.cmake was originally suggested by
@KrisThielemans

Change-Id: I9277e0c7ba730bffd938371859fd574a82248253
diff --git a/cmake/FindGlog.cmake b/cmake/FindGlog.cmake
index 1a7b6c0..13a43e7 100644
--- a/cmake/FindGlog.cmake
+++ b/cmake/FindGlog.cmake
@@ -345,6 +345,11 @@
   endif (GLOG_LIBRARY AND
     NOT "${LOWERCASE_GLOG_LIBRARY}" MATCHES ".*glog[^/]*")
 
+  # add glog::glog target
+  add_library(glog::glog INTERFACE IMPORTED)
+  target_include_directories(glog::glog INTERFACE ${GLOG_INCLUDE_DIRS})
+  target_link_libraries(glog::glog INTERFACE ${GLOG_LIBRARY})
+
   glog_reset_find_library_prefix()
 
 endif(NOT GLOG_FOUND)