platform/target: msm8996: Add support for new memory map

For 8996 two different types of memory configurations are supported
based on 3gb & 4gb ddr respectively. Add changes to support the new
memory maps.

Change-Id: I180dde3e394db1173f8407c00947072796f4efd6
diff --git a/include/platform.h b/include/platform.h
index 0c59056..50ef337 100644
--- a/include/platform.h
+++ b/include/platform.h
@@ -70,4 +70,5 @@
 uint32_t platform_detect_panel();
 uint32_t platform_get_max_periph();
 int platform_is_msm8996();
+uint64_t platform_get_ddr_start();
 #endif