x86/platform/intel/iosf: Add better description of IOSF driver in config

Adds better description of IOSF driver to determine when it
should be enabled. Also moves the Kconfig option to "Processor
type and features" menu from main configuration menu.

Signed-off-by: David E. Box <david.e.box@linux.intel.com>
Link: http://lkml.kernel.org/r/1411017231-20807-3-git-send-email-david.e.box@linux.intel.com


Signed-off-by: Ingo Molnar <mingo@kernel.org>