ANDROID: Use rq_clock_task without CONFIG_SMP

Fix build error caused by guarding rq_clock_task_mult with CONFIG_SMP.

Issue was not seen in original commit as test case was UM Linux, which
does not enable CONFIG_CFS_BANDWIDTH.

>> kernel/sched/fair.c:4791:40: error: implicit declaration of function 'rq_clock_task_mult' [-Werror,-Wimplicit-function-declaration]
                   cfs_rq->throttled_clock_task_time += rq_clock_task_mult(rq) -

Change-Id: Id3392c37ba1b2bfe78c89bc4b1ca01b920164a35
Reported-by: kernel test robot <lkp@intel.com>
Fixes: 567d65e536 ("ANDROID: Guard rq_clock_task_mult with CONFIG_SMP")
Signed-off-by: Elliot Berman <quic_eberman@quicinc.com>

kernel/sched/sched.h

@@ -1203,6 +1203,11 @@ static inline u64 rq_clock_task_mult(struct rq *rq)
 
 	return per_cpu(clock_task_mult, cpu_of(rq));
 }
+#else
+static inline u64 rq_clock_task_mult(struct rq *rq)
+{
+	return rq_clock_task(rq);
+}
 #endif
 
 /**