sched/fair: Carve out logic to mark a group for asymmetric packing

sched/fair: Carve out logic to mark a group for asymmetric packing

Create a separate function, sched_asym(). A subsequent changeset will
introduce logic to deal with SMT in conjunction with asmymmetric
packing. Such logic will need the statistics of the scheduling
group provided as argument. Update them before calling sched_asym().

Co-developed-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ricardo Neri <ricardo.neri-calderon@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Reviewed-by: Len Brown <len.brown@intel.com>
Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org>
Link: https://lkml.kernel.org/r/20210911011819.12184-6-ricardo.neri-calderon@linux.intel.com
(cherry picked from commit aafc917a3c31dcc76cb0279cd7617dda11b15f2a)
Signed-off-by: Brad Figg <brad.figg@canonical.com>