linux-user/mips: pick Loongson-3A4000 if a pre-r6 mips64 binary needs nan2008 Before this patch, we'd pick MIPS64R2-generic which does not have 2008 mode, so the binary would just fail to run without an explicit -cpu flag. Now it'll just work as in the pre-r6 mips32 case. Signed-off-by: Alex Rønne Petersen <alex@alexrp.com> Signed-off-by: Helge Deller <deller@gmx.de>