staging:rtl8192u: Remove unused RTL8258 bit mask definitions - Style

Remove the unused 'RTL8258' bit mask definitions. These definitions fail
the checkpatch CamelCase naming tests. Since the definitions are unused
in code they have been removed, rather then renaming.

This is a coding style change which should have no impact on runtime
code execution.

Signed-off-by: John Whitmore <johnfwhitmore@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>