de2_115_top.sv: Expose boot ROM file as a top-level parameter
de2_115_top.sv: Expose boot ROM file as a top-level parameter

This allows tools to set the boot ROM contents from command line

jbush001/NyuziProcessor,jbush001/NyuziProcessor,jbush001/NyuziProcessor,jbush001/NyuziProcessor,jbush001/NyuziProcessor,jbush001/NyuziProcessor