platform: generic: sophgo: add mango soc support

The mango cpu of sophgo is a 64 cores C920 CPU. The board with mango can
have at most two sockets. The CPU have the following features:

 1) support RV64GCV
 2) one seperate timer each cluster
 3) T-HEAD pmu device

Signed-off-by: Inochi Amaoto <inochiama@outlook.com>

platform/generic/Kconfig

@@ -51,6 +51,10 @@ config PLATFORM_STARFIVE_JH7110
 	bool "StarFive JH7110 support"
 	default n
 
+config PLATFORM_SOPHGO_MANGO
+	bool "Sophgo MANGO support"
+	default n
+
 source "$(OPENSBI_SRC_DIR)/platform/generic/andes/Kconfig"
 
 endif