wifi: iwlwifi: fix build when mvm/mld not configured

wifi: iwlwifi: fix build when mvm/mld not configured

When neither mvm nor mld are configured, we don't have the
iwl_bz_mac_cfg symbol and thus cannot check for it. But in
that case the relevant device entries aren't and cannot be
present, so just ifdef the test code for that.

Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202509170625.BAJBe7Bi-lkp@intel.com/
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Miri Korenblit <miriam.rachel.korenblit@intel.com>
Link: https://patch.msgid.link/20251019114304.615810979e7b.I9a215f955bb3208d99239be8496d19e0f186b4d0@changeid