hwc: Remove unused utility function

Cleaning up unused code in utils library.

Change-Id: I642f78897fa317f34bdcdba4df84db10ad9f7eb3
diff --git a/libhwcomposer/hwc_utils.cpp b/libhwcomposer/hwc_utils.cpp
index 8fb622f..0da52d8 100644
--- a/libhwcomposer/hwc_utils.cpp
+++ b/libhwcomposer/hwc_utils.cpp
@@ -1455,10 +1455,6 @@
     nwr = getIntersection(nwr, fbDisplayFrame);
 }
 
-bool isExternalActive(hwc_context_t* ctx) {
-    return ctx->dpyAttr[HWC_DISPLAY_EXTERNAL].isActive;
-}
-
 void closeAcquireFds(hwc_display_contents_1_t* list) {
     if(LIKELY(list)) {
         for(uint32_t i = 0; i < list->numHwLayers; i++) {
diff --git a/libhwcomposer/hwc_utils.h b/libhwcomposer/hwc_utils.h
index d419213..f838840 100644
--- a/libhwcomposer/hwc_utils.h
+++ b/libhwcomposer/hwc_utils.h
@@ -280,7 +280,6 @@
 bool isRotatorSupportedFormat(private_handle_t *hnd);
 //Returns true, if the layer is YUV or the layer has been rendered by CPU
 bool isRotationDoable(hwc_context_t *ctx, private_handle_t *hnd);
-bool isExternalActive(hwc_context_t* ctx);
 bool isAlphaScaled(hwc_layer_1_t const* layer);
 bool needsScaling(hwc_layer_1_t const* layer);
 bool isDownscaleRequired(hwc_layer_1_t const* layer);