binutils: older versions can be used for nios2

target/config/Config.in.binutils

@@ -39,7 +39,6 @@ config ADK_TOOLCHAIN_BINUTILS_2_26_1
 	depends on !ADK_TARGET_ARCH_H8300
 	depends on !ADK_TARGET_ARCH_LM32
 	depends on !ADK_TARGET_ARCH_NDS32
-	depends on !ADK_TARGET_ARCH_NIOS2
 
 config ADK_TOOLCHAIN_BINUTILS_2_25_1
 	bool "2.25.1"
@@ -50,7 +49,6 @@ config ADK_TOOLCHAIN_BINUTILS_2_25_1
 	depends on !ADK_TARGET_ARCH_H8300
 	depends on !ADK_TARGET_ARCH_MOXIE
 	depends on !ADK_TARGET_ARCH_NDS32
-	depends on !ADK_TARGET_ARCH_NIOS2
 	depends on !ADK_TARGET_CPU_CRIS_CRISV10
 
 config ADK_TOOLCHAIN_BINUTILS_2_24