[PATCH] IPMI: allow user to override the kernel IPMI daemon enable

After the previous patch to disable the kernel IPMI daemon if interrupts
were available, the issue of broken hardware was raised, and a reasonable
request to add an override was mode.  So here it is.

Allow the user to force the kernel ipmi daemon on or off.  This way,
hardware with broken interrupts or users that are not concerned with
performance can turn it on or off to their liking.

[akpm@osdl.org: save 4 bytes in vmlinux]
Signed-off-by: Corey Minyard <minyard@acm.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>