Input: UDP Client to provide motion and touch controls

An implementation of the cemuhook motion/touch protocol, this adds the
ability for users to connect several different devices to citra to send
direct motion and touch data to citra.

src/input_common/CMakeLists.txt

@@ -7,13 +7,18 @@ add_library(input_common STATIC
     main.h
     motion_emu.cpp
     motion_emu.h
+    udp/client.cpp
+    udp/client.h
+    udp/protocol.cpp
+    udp/protocol.h
+    udp/udp.cpp
+    udp/udp.h
 
     $<$<BOOL:${SDL2_FOUND}>:sdl/sdl.cpp sdl/sdl.h>
 )
 
 create_target_directory_groups(input_common)
-
-target_link_libraries(input_common PUBLIC core PRIVATE common)
+target_link_libraries(input_common PUBLIC core PRIVATE common ${Boost_LIBRARIES})
 
 if(SDL2_FOUND)
     target_link_libraries(input_common PRIVATE SDL2)