qcacld-3.0: Add capability to disable checksum for legacy links

Due to latency concerns on GEN1 PCIe attach checksum offload and TSO
features cannot be enabled for 802.11A/B/G legacy mode connections.
So add INI option to dynamically disable/enable checksum offload and TSO
based on the connection type.
Use netdev_update_features kernel API to adjust the netdev features
dynamically for existing registered netdev.

change-id: I0e44cb1789516e1bcee619be3581d826f45f265b
CRs-Fixed: 2732090
6 files changed