[chore] Move SDL check to the end of Device's probe function (#7682)

To avoid a few log lines on all platforms:

```
ffi.load: SDL2
ffi.load (warning): libSDL2.so: cannot open shared object file: No such file or directory
ffi.load: libSDL2-2.0.so
ffi.load (warning): libSDL2-2.0.so: cannot open shared object file: No such file or directory
ffi.load: libSDL2-2.0.so.0
ffi.load (warning): libSDL2-2.0.so.0: cannot open shared object file: No such file or directory
```

frontend/device.lua

@@ -2,10 +2,6 @@ local isAndroid, _ = pcall(require, "android")
 local util = require("ffi/util")
 
 local function probeDevice()
-    if util.isSDL() then
-        return require("device/sdl/device")
-    end
-
     if isAndroid then
         return require("device/android/device")
     end
@@ -40,6 +36,9 @@ local function probeDevice()
     if cervantes_test_stat then
         return require("device/cervantes/device")
     end
+    if util.isSDL() then
+        return require("device/sdl/device")
+    end
 
     -- add new ports here:
     --