Removed build time variable ENABLE_CPUSETS.

Use runtime check, cpuset_enabled(), instead of build time varianble
usually set in BoardConfog.mk.

Bug: 34726944

Test: Tested on Sailfish
      without cpuset mounted
      with cpuset mounted, but without schedtune
      with cpuset mounted and with schedtune

Change-Id: I00153628db62abfbaa0ba75d571ba1bda0611ff3
diff --git a/services/surfaceflinger/Android.mk b/services/surfaceflinger/Android.mk
index 170faa8..be537dc 100644
--- a/services/surfaceflinger/Android.mk
+++ b/services/surfaceflinger/Android.mk
@@ -159,10 +159,6 @@
 
 LOCAL_INIT_RC := surfaceflinger.rc
 
-ifneq ($(ENABLE_CPUSETS),)
-    LOCAL_CFLAGS += -DENABLE_CPUSETS
-endif
-
 ifeq ($(TARGET_USES_HWC2),true)
     LOCAL_CFLAGS += -DUSE_HWC2
 endif
diff --git a/services/surfaceflinger/main_surfaceflinger.cpp b/services/surfaceflinger/main_surfaceflinger.cpp
index 53a63bd..f151087 100644
--- a/services/surfaceflinger/main_surfaceflinger.cpp
+++ b/services/surfaceflinger/main_surfaceflinger.cpp
@@ -45,12 +45,10 @@
 
     set_sched_policy(0, SP_FOREGROUND);
 
-#ifdef ENABLE_CPUSETS
     // Put most SurfaceFlinger threads in the system-background cpuset
     // Keeps us from unnecessarily using big cores
     // Do this after the binder thread pool init
-    set_cpuset_policy(0, SP_SYSTEM);
-#endif
+    if (cpusets_enabled()) set_cpuset_policy(0, SP_SYSTEM);
 
     // initialize before clients can connect
     flinger->init();