First pass on the new SDL sensor API

CMakeLists.txt

@@ -750,6 +750,10 @@ if(SDL_HAPTIC)
   file(GLOB HAPTIC_SOURCES ${SDL2_SOURCE_DIR}/src/haptic/*.c)
   set(SOURCE_FILES ${SOURCE_FILES} ${HAPTIC_SOURCES})
 endif()
+if(SDL_SENSOR)
+  file(GLOB SENSOR_SOURCES ${SDL2_SOURCE_DIR}/src/sensor/*.c)
+  set(SOURCE_FILES ${SOURCE_FILES} ${SENSOR_SOURCES})
+endif()
 if(SDL_POWER)
   file(GLOB POWER_SOURCES ${SDL2_SOURCE_DIR}/src/power/*.c)
   set(SOURCE_FILES ${SOURCE_FILES} ${POWER_SOURCES})