platform: msm8916: Change SCRATCH memory policy

Change SCRATCH memory policy as write-back to improve more
access efficincy.

Change-Id: I0c439590433885eeb5b02c10d009acd08b070c24
diff --git a/platform/msm8916/platform.c b/platform/msm8916/platform.c
index 1531b28..6729667 100644
--- a/platform/msm8916/platform.c
+++ b/platform/msm8916/platform.c
@@ -66,7 +66,7 @@
 	{    A53_SS_BASE,       A53_SS_BASE,      A53_SS_SIZE,      IOMAP_MEMORY},
 	{    SYSTEM_IMEM_BASE,  SYSTEM_IMEM_BASE, 1,                COMMON_MEMORY},
 	{    MSM_SHARED_BASE,   MSM_SHARED_BASE,  1,                COMMON_MEMORY},
-	{    SCRATCH_ADDR,      SCRATCH_ADDR,     256,              COMMON_MEMORY},
+	{    SCRATCH_ADDR,      SCRATCH_ADDR,     256,              SCRATCH_MEMORY},
 	{    MIPI_FB_ADDR,      MIPI_FB_ADDR,     10,              COMMON_MEMORY},
 };