igc: Remove delay during TX ring configuration

Remove unnecessary delay during the TX ring configuration.
This will cause delay, especially during link down and
link up activity.

Furthermore, old SKUs like as I225 will call the reset_adapter
to reset the controller during TSN mode Gate Control List (GCL)
setting. This will add more time to the configuration of the
real-time use case.

It doesn't mentioned about this delay in the Software User Manual.
It might have been ported from legacy code I210 in the past.

Fixes: 13b5b7fd ("igc: Add support for Tx/Rx rings")
Signed-off-by: Muhammad Husaini Zulkifli <muhammad.husaini.zulkifli@intel.com>
Acked-by: Sasha Neftin <sasha.neftin@intel.com>
Tested-by: Naama Meir <naamax.meir@linux.intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>

drivers/net/ethernet/intel/igc/igc_main.c

@@ -711,7 +711,6 @@ static void igc_configure_tx_ring(struct igc_adapter *adapter,
 	/* disable the queue */
 	wr32(IGC_TXDCTL(reg_idx), 0);
 	wrfl();
-	mdelay(10);
 
 	wr32(IGC_TDLEN(reg_idx),
 	     ring->count * sizeof(union igc_adv_tx_desc));