Split the RsForEachStubParamStruct in two.

This patch splits the RsForEachStubParamStruct into two smaller structs, one
used specifically by the driver and the other by the expanded kernels.  Doing
so makes it clearer what data is used where.  In addition, fewer data are
copied between memory locations during kernel invocation.

Several fields that were not being used were removed from the structs.

Change-Id: I7788ef754add44463b17a6b571c7cde6e73b9712
diff --git a/cpu_ref/rsCpuScript.h b/cpu_ref/rsCpuScript.h
index f4ca1ed..d51e9e3 100644
--- a/cpu_ref/rsCpuScript.h
+++ b/cpu_ref/rsCpuScript.h
@@ -47,7 +47,7 @@
 class RsdCpuScriptImpl : public RsdCpuReferenceImpl::CpuScript {
 public:
     typedef void (*outer_foreach_t)(
-        const RsForEachStubParamStruct *,
+        const RsExpandKernelParams *,
         uint32_t x1, uint32_t x2,
         uint32_t instep, uint32_t outstep);
 #ifdef RS_COMPATIBILITY_LIB