sched: hmp: add read-only hmp domain sysfs file
In order to allow userspace to restrict known low-load tasks to
little CPUs, we must export this knowledge from the kernel or
expect userspace to make their own attempts at figuring it out.
Since we now have a userspace requirement for an HMP implementation
to always have at least some sysfs files, change the integration
so that it only depends upon CONFIG_SCHED_HMP rather than
CONFIG_HMP_VARIABLE_SCALE. Fix Kconfig text to match.
Signed-off-by: Chris Redpath <chris.redpath@arm.com>
Signed-off-by: Jon Medhurst <tixy@linaro.org>