[BNX2]: Optimize firmware loading.

This is a follow up to the patches from Denys Vlasenkos
<vda.linux@googlemail.com> to further optimize firmware loading.

1. In bnx2_init_cpus(), we allocate memory for decompression once
and use it repeatedly instead of doing this for every firmware image.

2. We eliminate the BSS and SBSS firmware sections in bnx2_fw*.h since
these are always zeros.

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