Fix {$LINKLIB} directives in SDL3_ttf

The {$LINKLIB} directives in SDL3_tff.pas were instructing the compiler
to link against the base SDL3 library, instead of SDL3_ttf.

Author: suve

units/SDL3_ttf.pas

@@ -66,7 +66,7 @@ interface
   {$IFDEF DARWIN}
     IMG_LibName = 'libSDL3_ttf.dylib';
     {$IFDEF FPC}
-      {$LINKLIB libSDL3}
+      {$LINKLIB libSDL3_ttf}
     {$ENDIF}
   {$ELSE}
     {$IFDEF FPC}
@@ -80,7 +80,7 @@ interface
 {$IFDEF MACOS}
   IMG_LibName = 'SDL3_ttf';
   {$IFDEF FPC}
-    {$linklib libSDL3}
+    {$linklib libSDL3_ttf}
   {$ENDIF}
 {$ENDIF}