gtemu.c: use gigatron.rom instead of ROMv1.rom
gtemu.c: use gigatron.rom instead of ROMv1.rom

- Independent of ROM version
- Same as done in the javascript emulator
- Same as in the revised printed manual

kervinck/gigatron-rom,kervinck/gigatron-rom,kervinck/gigatron-rom,kervinck/gigatron-rom,kervinck/gigatron-rom,kervinck/gigatron-rom,kervinck/gigatron-rom