This is part of work to run binaries created for the simple system
under Spike. Spike's default behaviour (after a weird 'rom' trampoline
at 0x1000) is to obey the entry point given in the ELF file. So let's
set it correctly.
Simple system is a basic verilator top-level testbench for running
executables. It has functionality for outputting text to a log file
and for the software to terminate the simulation