wifi: iwlwifi: Add helper function to extract device ID

Add iwl_trans_get_device_id() to extract the device ID
from the hw_id member in the iwl_trans structure.
hw_id member contains both sub-device ID and device ID,
with the device ID occupying bits 16 to 31.

Signed-off-by: Pagadala Yesu Anjaneyulu <pagadala.yesu.anjaneyulu@intel.com>
Signed-off-by: Miri Korenblit <miriam.rachel.korenblit@intel.com>
Link: https://patch.msgid.link/20250511195137.4411402701f2.I81cde20de05e3bb993977f8d4bbf90707819347f@changeid