Added stub Steam Controller sources to Android and iOS command line builds

configure.in

@@ -3366,6 +3366,7 @@ case "$host" in
             android)
                 AC_DEFINE(SDL_JOYSTICK_ANDROID, 1, [ ])
                 SOURCES="$SOURCES $srcdir/src/joystick/android/*.c"
+                SOURCES="$SOURCES $srcdir/src/joystick/steam/*.c"
                 have_joystick=yes
             ;;
           esac
@@ -3645,6 +3646,7 @@ AC_HELP_STRING([--enable-render-d3d], [enable the Direct3D render driver [[defau
         if test x$enable_joystick = xyes; then
             AC_DEFINE(SDL_JOYSTICK_MFI, 1, [ ])
             SOURCES="$SOURCES $srcdir/src/joystick/iphoneos/*.m"
+            SOURCES="$SOURCES $srcdir/src/joystick/steam/*.c"
             have_joystick=yes
         fi
         # Set up files for the haptic library