sched: Duplicate the rt.c file for the QHMP scheduler

The rt.c file has been duplicated to qhmp_rt.c as of commit:
33a7804b. The is necessary to avoid
the need for porting the subsequent cluster based CPU selection
logic to the QHMP scheduler.

Change-Id: I5c5039d73e315ec6462d70e2dc962b6193c1795d
Signed-off-by: Syed Rameez Mustafa <rameezmustafa@codeaurora.org>