Fixed some commands for scons

Changed platform to iphone but with x86 arch for simulator
Added arch parameter to 32 and 64 targets to get the correct files.

reference/compiling_for_ios.rst

@@ -34,7 +34,7 @@ Alternatively, you can run
 
 ::
 
-    $ scons p=isim bin/godot.isim.tools
+    $ scons p=iphone arch=x86 bin/godot.isim.tools
 
 for a Simulator executable.
 
@@ -44,9 +44,9 @@ It can be done in three steps, first compile 32 bit version, then compile 64 bit
 
 ::
 
-    $ scons p=iphone tools=no bits=32 target=release 
-    $ scons p=iphone tools=no bits=64 target=release
-    $ lipo -create bin/godot.iphone.opt.32 arm64 bin/godot.iphone.opt.64 -output bin/godot.iphone.opt.universal
+    $ scons p=iphone tools=no bits=32 target=release arch=arm
+    $ scons p=iphone tools=no bits=64 target=release arch=arm64
+    $ lipo -create bin/godot.iphone.opt.32 bin/godot.iphone.opt.64 -output bin/godot.iphone.opt.universal
 
 
 Run