glibc: nios2: Prevent selecting unsupported versions

Versions previous to glibc v2.21 do not support the Nios-II architecture
so disable them.

Signed-off-by: Ezequiel Garcia <ezequiel@vanguardiasur.com.ar>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

package/glibc/Config.in

@@ -33,6 +33,7 @@ choice
 	default BR2_GLIBC_VERSION_2_20
 
 config BR2_GLIBC_VERSION_2_20
+	depends on !BR2_nios2
 	bool "2.20"
 
 config BR2_GLIBC_VERSION_2_21