staging/slicoss: Use ethtool_ops instead of module_param.

ethtool_ops has attributes in sub struct ethtool_coalesce that
correspond to the parameters intagg_delay and dynamic_intagg. It is
preferable to set these properties with ethtool rather than
module_param, so create these attributes in adapter and set them using
ethtool_coalesce's rx_coalesce_usecs and rx_use_adaptive_coalesce.
(Outlined in TODO file)

Signed-off-by: Kevin Wern <kevin.m.wern@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>