Use bigger stack section in nSIM baseboard

Claudiu suggested to use a bigger stack section in nSIM baseboard, because
some tests might not pass because of a small stack.

Signed-off-by: Anton Kolesov <anton.kolesov@synopsys.com>
Better error message in DejaGNU test script

When unknown argument was passed to script that runs DejaGNU regression
tests it was printing "Usage" information, however it was completely unclear
what happens and which argument is invalid. This commit fixes both things:

1) Appropriate error message is printed, so that user will be aware what is
wrong
2) Error message will contain invalid argument so there will be no need to
manually search for invalid argument.

Signed-off-by: Anton Kolesov <anton.kolesov@synopsys.com>
Switch to nsimdrv instead of nsim_gdb

Nsim_gdb is an obsolete application, nsimdrv is a new alternative.

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