igbvf: remove unused fields from struct igbvf_adapter

igbvf: remove unused fields from struct igbvf_adapter

Remove following unused fields from struct igbvf_adapter that are never
referenced in the driver.

- blink_timer
- eeprom_wol
- fc_autoneg
- int_mode
- led_status
- mng_vlan_id
- polling_interval
- rx_dma_failed
- test_icr
- test_rx_ring
- test_tx_ring
- tx_dma_failed
- tx_fifo_head
- tx_fifo_size
- tx_head_addr

Also removed the following fields from struct igbvf_adapter since they
are never read or used after initialization by igbvf_probe() and igbvf_sw_init().

- bd_number
- rx_abs_int_delay
- tx_abs_int_delay
- rx_int_delay
- tx_int_delay

This changes simplify the igbvf driver by removing unused fields, which
improves maintenability.

Tested-by: Kohei Enju <enjuk@amazon.com>
Signed-off-by: Yuto Ohnuki <ytohnuki@amazon.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>