Add image computing oriented builtin functions

The new built-in functions covers inverse DCT, ADST and walsh transforms.

Change-Id: Ie7044da4a5becf2cc80d066a258211721a5939d4
diff --git a/driver/runtime/Android.mk b/driver/runtime/Android.mk
index ab8e33e..f67e14e 100755
--- a/driver/runtime/Android.mk
+++ b/driver/runtime/Android.mk
@@ -29,7 +29,12 @@
     rs_sampler.c \
     convert.ll \
     allocation.ll \
-    rsClamp.ll
+    rsClamp.ll \
+    rs_idct.c \
+    rs_dct.c \
+    rs_iadst.c  \
+    rs_fadst.c  \
+    rs_walsh.c
 
 clcore_files := \
     $(clcore_base_files) \