wifi: iwlwifi: mld: fix PM_SLEEP -Wundef warning

JIRA: https://issues.redhat.com/browse/RHEL-89168

commit 676b902
Author: Johannes Berg <johannes.berg@intel.com>
Date:   Tue Apr 1 06:45:55 2025 +0300

    wifi: iwlwifi: mld: fix PM_SLEEP -Wundef warning
    
    Config symbols are not defined if turned off, so need to
    use #ifdef, not #if.
    
    Fixes: d1e879e ("wifi: iwlwifi: add iwlmld sub-driver")
    Signed-off-by: Johannes Berg <johannes.berg@intel.com>
    Reviewed-by: Yedidya Ben Shimol <yedidya.ben.shimol@intel.com>
    Signed-off-by: Miri Korenblit <miriam.rachel.korenblit@intel.com>
    Link: https://patch.msgid.link/20250401064530.612020bcdaad.I4e885e6646576e29fb236250a1b5038d3f14b08e@changeid
    Signed-off-by: Johannes Berg <johannes.berg@intel.com>

Signed-off-by: Jose Ignacio Tornos Martinez <jtornosm@redhat.com>

Author: jtornosm

drivers/net/wireless/intel/iwlwifi/mld/iface.h

@@ -166,7 +166,7 @@ struct iwl_mld_vif {
 
 	struct iwl_mld_emlsr emlsr;
 
-#if CONFIG_PM_SLEEP
+#ifdef CONFIG_PM_SLEEP
 	struct iwl_mld_wowlan_data wowlan_data;
 #endif
 #ifdef CONFIG_IWLWIFI_DEBUGFS