net: mv643xx_eth: Factorize initial checksum and command preparation

Make the code more readable by moving the initial checksum setup
and the command/status preparation to its own function.

Signed-off-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --cc drivers/net/ethernet/marvell/mv643xx_eth.c
Simple merge