Fix gpu_power_level not being defined when compiling without KGSL (is it really needed?)

diff --git a/drivers/soc/qcom/msm_performance.c b/drivers/soc/qcom/msm_performance.c
index dbfb3f0..5f3e3b3 100644
--- a/drivers/soc/qcom/msm_performance.c
+++ b/drivers/soc/qcom/msm_performance.c
@@ -1384,6 +1384,8 @@ static void start_timer(struct cluster *cl)
        spin_unlock_irqrestore(&cl->timer_lock, flags);
 }
 
+int gpu_power_level;
+int gpu_max_power_level;
 static void check_cpu_load(struct cluster *cl, u64 now)
 {
        struct load_stats *pcpu_st;