util: m5: Makefile.x86: Provide the definition of the m5_dumpreset_stats
util: m5: Makefile.x86: Provide the definition of the m5_dumpreset_stats

This is required to provide the definition of m5_dumpreset_stats
required by the matrix multiply program which will be introduced
in next commit.

See this
http://pages.cs.wisc.edu/~david/courses/cs752/Fall2015/wiki/index.php?n=Main.Homework3

SanchayanMaity/gem5,SanchayanMaity/gem5,SanchayanMaity/gem5,SanchayanMaity/gem5,SanchayanMaity/gem5,SanchayanMaity/gem5,SanchayanMaity/gem5