emscripten: obey enable-misc/SDL_MISC settings

configure

@@ -26683,8 +26683,11 @@ $as_echo "#define SDL_AUDIO_DRIVER_EMSCRIPTEN 1" >>confdefs.h
         CheckClockGettime
         CheckEmscriptenGLES
 
-        SOURCES="$SOURCES $srcdir/src/misc/emscripten/*.c"
-        have_misc=yes
+        # Set up files for the misc library
+        if test x$enable_misc = xyes; then
+            SOURCES="$SOURCES $srcdir/src/misc/emscripten/*.c"
+            have_misc=yes
+        fi
 
          # Set up files for the power library
         if test x$enable_power = xyes; then
@@ -26695,7 +26698,7 @@ $as_echo "#define SDL_POWER_EMSCRIPTEN 1" >>confdefs.h
             have_power=yes
         fi
 
-        # Set up files for the power library
+        # Set up files for the joystick library
         if test x$enable_joystick = xyes; then
 
 $as_echo "#define SDL_JOYSTICK_EMSCRIPTEN 1" >>confdefs.h