HyperSparc support

To make a long story short :
2.4.27 (shipped with splack-beta) works UP on HyperSparc
(and it seems _very_ stable).
2.4.27 (recompiled) doesn\'t work SMP on HyperSparcs
(crash after 2 or 3 lines of kernel output at boot).
Test hardware :
SparcStation 20
2x HS125-1024 (RT626 with 1024K L2)

Cheers

Fran?ois Cami (Stilgar)