wifi: iwlwifi: remove PM mode and send-in-D3

Simplify the logic here by tracking only suspended as a
status bit, and remove CMD_SEND_IN_D3 completely. There
is no value, since the op-mode sets the state and also
sends the commands.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Reviewed-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Miri Korenblit <miriam.rachel.korenblit@intel.com>
Link: https://patch.msgid.link/20250503224231.cc3360761f1e.I72261afc42cee8983198b4660b7d38b7df7963da@changeid