Update Dejagnu CPU options

nSIM options to choose CPU and is version changes from nsim_isa_<core>=1 to
the pair nsim_isa_family= nsim_isa_core= options. This patch updates Dejagnu
to use those options when testing with standalone nSIM.

Signed-off-by: Anton Kolesov <Anton.Kolesov@synopsys.com>