gpu: ion: include msm-specific ion header

All msm_ion clients need to use <linux/msm_ion.h> instead of
<linux/ion.h>

Change-Id: I4f999e301d147ec3242a33ee75b10b6501d42a70
Signed-off-by: Mitchel Humpherys <mitchelh@codeaurora.org>
diff --git a/drivers/gpu/ion/ion_heap.c b/drivers/gpu/ion/ion_heap.c
index 6ea49db..165a7bf 100644
--- a/drivers/gpu/ion/ion_heap.c
+++ b/drivers/gpu/ion/ion_heap.c
@@ -18,6 +18,7 @@
 #include <linux/err.h>
 #include <linux/ion.h>
 #include "ion_priv.h"
+#include <linux/msm_ion.h>
 
 struct ion_heap *ion_heap_create(struct ion_platform_heap *heap_data)
 {