msm: board: reserve mdp writeback memory

The memory allocation happens on the display mdp driver side. This
separation of writeback buffers from the frame buffer is mainly for
content security.

Change-Id: I404b5f8db01dd5ed940916d7d46a8ace2d295e3a
Signed-off-by: Huaibin Yang <huaibiny@codeaurora.org>
diff --git a/arch/arm/mach-msm/board-8930.c b/arch/arm/mach-msm/board-8930.c
index 3acf31f..41074d1 100644
--- a/arch/arm/mach-msm/board-8930.c
+++ b/arch/arm/mach-msm/board-8930.c
@@ -326,11 +326,18 @@
 	msm8930_reserve_table[MEMTYPE_EBI1].size += MSM_ION_ADSP_SIZE;
 #endif
 }
+
+static void __init reserve_mdp_memory(void)
+{
+	msm8930_mdp_writeback(msm8930_reserve_table);
+}
+
 static void __init msm8930_calculate_reserve_sizes(void)
 {
 	size_pmem_devices();
 	reserve_pmem_memory();
 	reserve_ion_memory();
+	reserve_mdp_memory();
 }
 
 static struct reserve_info msm8930_reserve_info __initdata = {