e1000: Use more constant definitions

e1000: Use more constant definitions

The definitions for E1000_VFTA_ENTRY_SHIFT, E1000_VFTA_ENTRY_MASK, and
E1000_VFTA_ENTRY_BIT_SHIFT_MASK were copied from:
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/tree/drivers/net/ethernet/intel/e1000/e1000_hw.h?h=v6.0.9#n306

The definitions for E1000_NUM_UNICAST, E1000_MC_TBL_SIZE, and
E1000_VLAN_FILTER_TBL_SIZE were copied from:
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/tree/drivers/net/ethernet/intel/e1000/e1000_hw.h?h=v6.0.9#n707

Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Jason Wang <jasowang@redhat.com>