strace: enable supported nios2 arch

Support for Nios-II has been added in strace release 4.11.

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