iwlwifi: mvm: don't send keys when entering D3

iwlwifi: mvm: don't send keys when entering D3

In the past, we needed to program the keys when entering D3. This was
since we replaced the image. However, now that there is a single
image, this is no longer needed.  Note that RSC is sent separately in
a new command.  This solves issues with newer devices that support PN
offload. Since driver re-sent the keys, the PN got zeroed and the
receiver dropped the next packets, until PN caught up again.

Signed-off-by: Sara Sharon <sara.sharon@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>