staging: rtl8187se: Removed non-existent function headers from r8180.h

Cleaned up r8180.h header file by removing headers of functions that
don't exist

Signed-off-by: Maxim Mikityanskiy <maxtram95@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>