staging: r8188eu: Remove unneeded prototypes from include/odm.h

This header contains a number of routines that do not to be available
globally. Once this change was made, a number of the routines were not
used, and could be removed.

Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>