[ECOS] Enable EDB7xxx interrupts

[Trenton D. Adams]

> Did you use the create_interrupt() mechanism to attach to 
> this interrupt? If not, the system will see it, treat it as 
> spurious and simply clear and ignore it.
> 
> The whole idea of having the OS handle this stuff is so that common 
> mechanisms work, at least in a similar fashion, across 
> different platforms. Because of that, you can't really expect 
> to just poll registers to see what's happening.

Ya, I understand the fact that I should be using the eCos functions.  I
just figured I might not HAVE to.  But, it makes total sense now.

Thanks Gary.