cpuinfo: Added SDL_GetSystemPageSize.

Fixes #14201.

test/testsymbols.c

@@ -1339,6 +1339,7 @@ const static struct {
     SDL_SYMBOL_ITEM(SDL_LoadPNG),
     SDL_SYMBOL_ITEM(SDL_SavePNG_IO),
     SDL_SYMBOL_ITEM(SDL_SavePNG),
+    SDL_SYMBOL_ITEM(SDL_GetSystemPageSize),
     /* extra symbols go here (don't modify this line) */
     { NULL, NULL }
 };