powerHAL: Removes the system call for reducing the refresh rate when the
device is in low power mode.

Logic shifted to the generic frameworks code because it isn't device
specific.

Change-Id: I3d5dbb7c032381dc2590930ea3bf0ab9384ca6a3
diff --git a/power/power_hammerhead.c b/power/power_hammerhead.c
index a9f497c..49eabb5 100644
--- a/power/power_hammerhead.c
+++ b/power/power_hammerhead.c
@@ -368,8 +368,6 @@
                          freq_set[cpu] = true;
                      }
                  }
-                 // reduces the refresh rate
-                 system("service call SurfaceFlinger 1016 i32 1");
              } else {
                  low_power_mode = false;
                  for (cpu = 0; cpu < TOTAL_CPUS; cpu++) {
@@ -378,8 +376,6 @@
                          freq_set[cpu] = false;
                      }
                  }
-                 // restores the refresh rate
-                 system("service call SurfaceFlinger 1016 i32 0");
              }
              pthread_mutex_unlock(&low_power_mode_lock);
              break;