i40e: Remove unused i40e_dcb_hw_get_num_tc

The last useof i40e_dcb_hw_get_num_tc() was removed in 2022 by
commit fe203715 ("Revert "i40e: Fix reset bw limit when DCB enabled
with 1 TC"")

Remove it.

Signed-off-by: Dr. David Alan Gilbert <linux@treblig.org>
Reviewed-by: Kalesh AP <kalesh-anakkur.purayil@broadcom.com>
Reviewed-by: Tony Nguyen <anthony.l.nguyen@intel.com>
Link: https://patch.msgid.link/20250102173717.200359-10-linux@treblig.org


Signed-off-by: Jakub Kicinski <kuba@kernel.org>