msm8974: Add download mode entrance on power-on

Add platform specific function that writes force download cookie
to the appropriate address to invoke download mode entrance
upon restart

Change-Id: I4dd4faadb0a0ece78c8992b49ca505cd475aa284
diff --git a/platform/msm8974/include/platform/iomap.h b/platform/msm8974/include/platform/iomap.h
index f18064e..12f0015 100644
--- a/platform/msm8974/include/platform/iomap.h
+++ b/platform/msm8974/include/platform/iomap.h
@@ -44,6 +44,8 @@
 #define RESTART_REASON_ADDR         (RPM_MSG_RAM_BASE     + 0x65C)
 #define RESTART_REASON_ADDR_V2      (MSM_SHARED_IMEM_BASE + 0x65C)
 
+#define FORCE_DLOAD_MODE_ADDR_V2    (MSM_SHARED_IMEM_BASE + 0xFE0)
+
 #define KPSS_BASE                   0xF9000000
 
 #define MSM_GIC_DIST_BASE           KPSS_BASE