ixgbe: Support sending custom Ethernet FCS.
ixgbe: Support sending custom Ethernet FCS.

Including bad FCS, used generate frames with bad FCS
to test other system's handling of RX of bad packets.

Signed-off-by: Ben Greear <a73a03e3b44aa05185cea6823d080c09a7808534@candelatech.com>
Tested-by: Jeff Pieper <89ae28dca346dcf475c1c4c5ccad0a12c81be577@intel.com>
Signed-off-by: Jeff Kirsher <87e35f5be20bb3e67f4ba6b86f5f6be3085b1b3a@intel.com>

TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs