msm: rq_stats: remove io_is_busy from load computation

Existing runqueue implementatoin assumes io_is_busy is set.
This causes huge frequency scaling. So remove this assumption
from the code.

CR-fixed: 455060
Change-Id: Iec3e5a4d2c787a51e23961b54292f9ab59e69ea2
Signed-off-by: Murali Nalajala <mnalajal@codeaurora.org>