wifi: iwlwifi: pcie: make _iwl_trans_pcie_gen2_stop_device() static

This function isn't used outside the file it's implemented in,
so make it static.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Miri Korenblit <miriam.rachel.korenblit@intel.com>
Link: https://patch.msgid.link/20241231135726.060c01653d4e.I3f0675b3977e474b633ff10965fe6512f34ae593@changeid


Signed-off-by: Johannes Berg <johannes.berg@intel.com>