qede: use ethtool_rx_flow_rule() to remove duplicated parser code

The qede driver supports for ethtool_rx_flow_spec and flower, both
codebases look very similar.

This patch uses the ethtool_rx_flow_rule() infrastructure to remove the
duplicated ethtool_rx_flow_spec parser and consolidate ACL offload
support around the flow_rule infrastructure.

Furthermore, more code can be consolidated by merging
qede_add_cls_rule() and qede_add_tc_flower_fltr(), these two functions
also look very similar.

This driver currently provides simple ACL support, such as 5-tuple
matching, drop policy and queue to CPU.

Drivers that support more features can benefit from this infrastructure
to save even more redundant codebase.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>