be2net: shorten AMAP_GET/SET_BITS() macro calls

The AMAP_GET/SET_BITS() macro calls take structure name as a parameter
and hence are long and span more than one line. Replace these calls
with a wrapper macros for RX/Tx compls and TX wrb. This results in fewer
lines and more readable code in be_main.c

Signed-off-by: Sathya Perla <sathya.perla@emulex.com>
Signed-off-by: David S. Miller <davem@davemloft.net>