The purpose of rx_training had changed after last update. Currently it
is not supposed to help with providing static parameters for porting
layer. Instead, it aims to suit the parameters per connection.

Change-Id: I2a146b71e2e20bd264c090a9a627d0b6bc56e052
Signed-off-by: Grzegorz Jaszczyk <jaz@semihalf.com>