VISWS support for 2.5.24

Hi all,

attached patch is a forward port of Sourceforge VISWS support patch.

Changes since 2.5.23:
1) make VISWS sound driver compile again;
2) replace probe_irq_on(), probe_irq_off() with dummy inlines, instead of ugly #ifdef's in irq.c.

Compiles, untested. Please take a look at it.

--
Andrey Panin | Embedded systems software engineer
[email protected] | PGP key: wwwkeys.eu.pgp.net