gcc: 7.1 supports riscv

target/config/Config.in.compiler

@@ -45,8 +45,6 @@ config ADK_TOOLCHAIN_GCC_7
 	depends on !ADK_TARGET_ARCH_METAG
 	depends on !ADK_TARGET_ARCH_NDS32
 	depends on !ADK_TARGET_ARCH_OR1K
-	depends on !ADK_TARGET_ARCH_RISCV32
-	depends on !ADK_TARGET_ARCH_RISCV64
 	select ADK_DISABLE_HONOUR_CFLAGS
 
 config ADK_TOOLCHAIN_GCC_6