staging: r8712u: Merging Realtek's latest (v2.6.6). New decl's and defines.

Removed unnecessary casts in kfree calls.
A few new types, defines and prototypes.

Signed-off-by: Ali Bahar <ali@internetDog.org>
Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>