S2io: hardware fixes

Hi,
Following are the code changes addressing the hardware errata mentioned in user guide.

1. Xena3's with a set of subsystem IDs had Link LED problems, fixed that specifically for
them.
2. To write into the Keyed Mac_Cfg register to enable broadcast, writing two 32 bit writes
into it along with a write to the key register rather than a single write
to key and a 64
bit write to mac_cfg. This is necessary on 32 bit systems where a
writeq(64 bit write) is
actually two writel (32 bit writes).
3. Writes to some special registers mentioned in UG is being done by a special macro which
defines which 32 bits of the 64 bit register is to be written first.
Again this applies
only on 32 bit systems.
4. Configured pause frame related water marks and a shared_split value which describes the
Max TXDMA related split transaction that can be used without giving room
for the Rx
transactions.
5. The mac_rmac_err_reg R1 register will be cleared in the interrupt handler itself rather
than in the scheduled task as was being done previously.
6. Even on PCC_FB_ECC error the card will be reset by disabling adapter enable bit.

no objections to this patch