bnx2: Rename register read and write macros

with BNX2_ prefix for namespace consistency.  Currently, these macro names
conflict with similar macros in bnx2x.h, preventing the cnic driver from
including both bnx2.h and bnx2x.h.  Including bnx2x.h in cnic.c will remove
many redundant definitions and simplify the interface.

Signed-off-by: Michael Chan <mchan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>