android: dri: use the installed libdrm headers

Saves us a few lines and brings us closer to the automake build.
Drop DRM_TOP as it's not longer used.

Signed-off-by: Emil Velikov <emil.l.velikov@gmail.com>
diff --git a/Android.mk b/Android.mk
index b50a8e0..591c2fc 100644
--- a/Android.mk
+++ b/Android.mk
@@ -38,7 +38,6 @@
 MESA_COMMON_MK := $(MESA_TOP)/Android.common.mk
 MESA_PYTHON2 := python
 
-DRM_TOP := external/drm
 DRM_GRALLOC_TOP := hardware/drm_gralloc
 
 classic_drivers := i915 i965
diff --git a/src/mesa/drivers/dri/Android.mk b/src/mesa/drivers/dri/Android.mk
index e0cf51c..5cb6d7b 100644
--- a/src/mesa/drivers/dri/Android.mk
+++ b/src/mesa/drivers/dri/Android.mk
@@ -37,8 +37,7 @@
 MESA_DRI_C_INCLUDES := \
 	$(call intermediates-dir-for,STATIC_LIBRARIES,libmesa_dri_common) \
 	$(addprefix $(MESA_TOP)/, $(mesa_dri_common_INCLUDES)) \
-	$(DRM_TOP) \
-	$(DRM_TOP)/include/drm \
+	$(TARGET_OUT_HEADERS)/libdrm \
 	external/expat/lib
 
 MESA_DRI_WHOLE_STATIC_LIBRARIES := \
diff --git a/src/mesa/drivers/dri/i915/Android.mk b/src/mesa/drivers/dri/i915/Android.mk
index c4f74d9..02052f8 100644
--- a/src/mesa/drivers/dri/i915/Android.mk
+++ b/src/mesa/drivers/dri/i915/Android.mk
@@ -38,8 +38,7 @@
 
 LOCAL_C_INCLUDES := \
 	$(addprefix $(MESA_TOP)/,$(i915_INCLUDES)) \
-	$(MESA_DRI_C_INCLUDES) \
-	$(DRM_TOP)/intel
+	$(MESA_DRI_C_INCLUDES)
 
 LOCAL_SRC_FILES := \
 	$(i915_FILES)
diff --git a/src/mesa/drivers/dri/i965/Android.mk b/src/mesa/drivers/dri/i965/Android.mk
index 2c6446f..7575882 100644
--- a/src/mesa/drivers/dri/i965/Android.mk
+++ b/src/mesa/drivers/dri/i965/Android.mk
@@ -42,8 +42,7 @@
 
 LOCAL_C_INCLUDES := \
 	$(i965_INCLUDES) \
-	$(MESA_DRI_C_INCLUDES) \
-	$(DRM_TOP)/intel
+	$(MESA_DRI_C_INCLUDES)
 
 LOCAL_SRC_FILES := \
 	$(i965_FILES)