Enable host build for gralloc

bug: 116712605

- No libdl needed on host
- Define PAGE_SIZE
- Include gralloc in build

+ Consolidate a few build script conditionals
  in egl Android.mk
+ Remove unused Callstack.h

Change-Id: I2e5f8050971d41e7ae26910ce6bd43dad114e5c5
diff --git a/Android.mk b/Android.mk
index 0c8748e..97452fe 100644
--- a/Android.mk
+++ b/Android.mk
@@ -57,6 +57,7 @@
     -DANDROID \
     -DGL_GLEXT_PROTOTYPES \
     -fvisibility=default \
+    -DPAGE_SIZE=4096 \
 
 endif # GOLDFISH_OPENGL_BUILD_FOR_HOST
 
@@ -136,9 +137,10 @@
 include $(GOLDFISH_OPENGL_PATH)/system/GLESv1/Android.mk
 include $(GOLDFISH_OPENGL_PATH)/system/GLESv2/Android.mk
 
+include $(GOLDFISH_OPENGL_PATH)/system/gralloc/Android.mk
+
 ifneq (true,$(GOLDFISH_OPENGL_BUILD_FOR_HOST))
 
-include $(GOLDFISH_OPENGL_PATH)/system/gralloc/Android.mk
 include $(GOLDFISH_OPENGL_PATH)/system/egl/Android.mk
 
 endif # !GOLDFISH_OPENGL_BUILD_FOR_HOST