switch aw & cw to target ARMv7

*** 758,769 ****
           */
  #if defined(AW_TARGET_arm)
          if (as64) {
                  return (error("no 64-bit aw target for arm"));
          } else {
!                 newae(as, "-march=armv6k");
!                 newae(as, "-mfpu=vfpv2");
                  newae(as, "-mfloat-abi=hard");
          }
  #endif
  
          if (srcfile == NULL)
--- 758,769 ----
           */
  #if defined(AW_TARGET_arm)
          if (as64) {
                  return (error("no 64-bit aw target for arm"));
          } else {
!                 newae(as, "-march=armv7-a");
!                 newae(as, "-mfpu=vfpv3-d16");
                  newae(as, "-mfloat-abi=hard");
          }
  #endif
  
          if (srcfile == NULL)