riscv: Modify generic codes to support RISC-V

Support common commands bdinfo and image format,
also modify common generic flow for RISC-V.

Signed-off-by: Rick Chen <rick@andestech.com>
Signed-off-by: Rick Chen <rickchen36@gmail.com>
Signed-off-by: Greentime Hu <green.hu@gmail.com>
Reviewed-by: Tom Rini <trini@konsulko.com>
diff --git a/arch/Kconfig b/arch/Kconfig
index 0b12ed9..762230c 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -54,6 +54,10 @@
 	select HAVE_PRIVATE_LIBGCC
 	select SUPPORT_OF_CONTROL
 
+config RISCV
+	bool "riscv architecture"
+	select SUPPORT_OF_CONTROL
+
 config SANDBOX
 	bool "Sandbox"
 	select BOARD_LATE_INIT
@@ -194,3 +198,4 @@
 source "arch/sh/Kconfig"
 source "arch/x86/Kconfig"
 source "arch/xtensa/Kconfig"
+source "arch/riscv/Kconfig"