mediatek: Add jedec info

Add jedec info for mt8173, mt8183, and mt8192.

[1] http://www.softnology.biz/pdf/JEP106AV.pdf

Signed-off-by: Hsin-Yi Wang <hsinyi@chromium.org>
Change-Id: Iab36fd580131f0b09b27223fba0e9d1e187d9196
diff --git a/plat/mediatek/mt8173/include/platform_def.h b/plat/mediatek/mt8173/include/platform_def.h
index 22129db..d340422 100644
--- a/plat/mediatek/mt8173/include/platform_def.h
+++ b/plat/mediatek/mt8173/include/platform_def.h
@@ -51,6 +51,8 @@
 					 PLATFORM_CLUSTER_COUNT +	\
 					 PLATFORM_CORE_COUNT)
 
+#define SOC_CHIP_ID                     U(0x8173)
+
 /*******************************************************************************
  * Platform memory map related constants
  ******************************************************************************/