mm-video: vidc: Skip pmem function when device uses ION

Skip compilation of pmem functions if a device uses ION.  This
eliminates dependency on kernel pmem definitions.

Change-Id: If77fb21e352ea8f0d8721baef9b8dbe8308266c1
diff --git a/mm-video/vidc/vdec/src/omx_vdec_msm8974.cpp b/mm-video/vidc/vdec/src/omx_vdec_msm8974.cpp
index bd23fec..e41e9f9 100644
--- a/mm-video/vidc/vdec/src/omx_vdec_msm8974.cpp
+++ b/mm-video/vidc/vdec/src/omx_vdec_msm8974.cpp
@@ -7551,6 +7551,7 @@
     return OMX_ErrorNone;
 }
 
+#ifndef USE_ION
 bool omx_vdec::align_pmem_buffers(int pmem_fd, OMX_U32 buffer_size,
                                   OMX_U32 alignment)
 {
@@ -7569,6 +7570,7 @@
   }
   return true;
 }
+#endif
 #ifdef USE_ION
 int omx_vdec::alloc_map_ion_memory(OMX_U32 buffer_size,
               OMX_U32 alignment, struct ion_allocation_data *alloc_data,