Fix enabling SDL_DYNAMIC_API in OpenWatcom builds

src/dynapi/SDL2.exports

@@ -1,5 +1,6 @@
 # Windows exports file for Watcom
 # DO NOT EDIT THIS FILE BY HAND. It is autogenerated by gendynapi.pl.
+++'_SDL_DYNAPI_entry'.'SDL2.dll'.'SDL_DYNAPI_entry'
 ++'_SDL_SetError'.'SDL2.dll'.'SDL_SetError'
 ++'_SDL_Log'.'SDL2.dll'.'SDL_Log'
 ++'_SDL_LogVerbose'.'SDL2.dll'.'SDL_LogVerbose'

src/dynapi/SDL_dynapi.h

@@ -61,8 +61,6 @@
 #define SDL_DYNAMIC_API 0  /* vitasdk doesn't support dynamic linking */
 #elif defined(__NGAGE__)
 #define SDL_DYNAMIC_API 0  /* The N-Gage doesn't support dynamic linking either */
-#elif defined(__OS2__) || defined(__WATCOMC__)
-#define SDL_DYNAMIC_API 0  /* see github bugs #5667 and #5669 */
 #elif defined(DYNAPI_NEEDS_DLOPEN) && !defined(HAVE_DLOPEN)
 #define SDL_DYNAMIC_API 0  /* we need dlopen(), but don't have it.... */
 #endif