ice: Avoid setting default Rx VSI twice in switchdev setup

As part of switchdev environment setup, uplink VSI is configured as
default for both Tx and Rx. Default Rx VSI is also used by promiscuous
mode. If promisc mode is enabled and an attempt to enter switchdev mode
is made, the setup will fail because Rx VSI is already configured as
default (rule exists).

Reproducer:
  devlink dev eswitch set $PF1_PCI mode switchdev
  ip l s $PF1 up
  ip l s $PF1 promisc on
  echo 1 > /sys/class/net/$PF1/device/sriov_numvfs

In switchdev setup, use ice_set_dflt_vsi() instead of plain
ice_cfg_dflt_vsi(), which avoids repeating setting default VSI for Rx if
it's already configured.

Fixes: 50d62022 ("ice: default Tx rule instead of to queue")
Reported-by: Sujai Buvaneswaran <sujai.buvaneswaran@intel.com>
Closes: https://lore.kernel.org/intel-wired-lan/PH0PR11MB50138B635F2E5CEB7075325D961F2@PH0PR11MB5013.namprd11.prod.outlook.com


Reviewed-by: Martyna Szapar-Mudlaw <martyna.szapar-mudlaw@linux.intel.com>
Signed-off-by: Marcin Szycik <marcin.szycik@linux.intel.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Tested-by: Sujai Buvaneswaran <sujai.buvaneswaran@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
Link: https://patch.msgid.link/20250224190647.3601930-3-anthony.l.nguyen@intel.com


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