OpenBSD neither provides nor requires libdl and librt.

CMakeLists.txt

@@ -415,7 +415,7 @@ if(ANDROID)
 	# We are cross compiling, search only the toolchain for libraries and includes
 	SET(CMAKE_FIND_ROOT_PATH_MODE_LIBRARY ONLY)
 	SET(CMAKE_FIND_ROOT_PATH_MODE_INCLUDE ONLY)
-elseif(NOT APPLE)
+elseif(NOT APPLE AND NOT CMAKE_SYSTEM_NAME MATCHES OpenBSD)
 	list(APPEND LIBS rt)
 endif()
 

Source/Core/Common/CMakeLists.txt

@@ -93,7 +93,7 @@ elseif(USE_X11)
     set(LIBS ${LIBS} ${XRANDR_LIBRARIES})
 endif()
 
-if(NOT CMAKE_SYSTEM_NAME MATCHES FreeBSD)
+if(${CMAKE_SYSTEM_NAME} STREQUAL "Linux")
 	set(LIBS ${LIBS} dl)
 endif()
 

Source/Core/DolphinWX/CMakeLists.txt

@@ -67,7 +67,7 @@ endif()
 
 set(WXLIBS ${wxWidgets_LIBRARIES})
 
-if(NOT CMAKE_SYSTEM_NAME MATCHES FreeBSD)
+if(${CMAKE_SYSTEM_NAME} STREQUAL "Linux")
 	set(WXLIBS ${WXLIBS} dl)
 endif()