Changed ARCv2 EM option from -mEM to -mav2em
Merge pull request #1 from foss-for-synopsys-dwc-arc-processors/claudiu-gcc-4.8-ChangedEMDriverOption

Changed ARCv2 EM option from -mEM to -mav2em

  * doc/invoke.texi: Change the option -mcpu=EM into -mcpu=ARCv2EM, and change the -mEM driver option to -mav2em
  * common/config/arc/arc-common.c:  Likewise
  * config/arc/arc-opts.h: Likewise
  * config/arc/arc.c: Likewise
  * config/arc/arc.h: Likewise
  * config/arc/arc.opt: Likewise