iwlwifi: rename iwl-4695-rs to iwl-agn-rs

This patch renames iwl-4965-rs to iwl-agn-rs as it provides
rate scale capability for all AGN capable iwlwifi drivers.

Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Zhu Yi <yi.zhu@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>