[PATCH 2.6.31] ixp4xx: arch_idle() documentation fixup

Mikael Pettersson [off-list ref] writes:

So this patch:
- adds a comment before the #if 0 to explain why
  cpu_do_idle() mustn't be called on ixp4xx
- removes the obsolete test of hlt_counter and the
  obsolete parameter to cpu_do_idle()

Thanks a lot, Mikael.

This is purely a documentation fixup and changes no
generated code. Even so, it has been tested on an
ixp420 machine (ds101).

:-)
-- 
Krzysztof Halasa