staging: r8188eu: remove RFType member of odm_dm_struct structure

rf_type is always equal to ODM_1T1R.
So, only RF PATH A exists for r8188eu device...

Signed-off-by: Ivan Safonov <insafonov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>