mbw: added 1.1 version of simple memory bandwidth benchmark

mbw: added 1.1 version of simple memory bandwidth benchmark

Results from my devices:

root@bug:~# mbw 16|grep AVG
AVG     Method: MEMCPY  Elapsed: 0.16403        MiB: 16.00000   Copy: 97.544 MiB/s
AVG     Method: DUMB    Elapsed: 0.12401        MiB: 16.00000   Copy: 129.023 MiB/s
AVG     Method: MCBLOCK Elapsed: 0.09725        MiB: 16.00000   Copy: 164.519 MiB/s

root@at91sam9263ek:~# mbw 16|grep AVG
AVG     Method: MEMCPY  Elapsed: 0.30546        MiB: 16.00000   Copy: 52.381 MiB/s
AVG     Method: DUMB    Elapsed: 0.13668        MiB: 16.00000   Copy: 117.064 MiB/s
AVG     Method: MCBLOCK Elapsed: 0.15507        MiB: 16.00000   Copy: 103.181 MiB/s

root@vortex86sx:~# mbw 16|grep AVG
AVG     Method: MEMCPY  Elapsed: 0.55531        MiB: 16.00000   Copy: 28.813 MiB/s
AVG     Method: DUMB    Elapsed: 1.04163        MiB: 16.00000   Copy: 15.361 MiB/s
AVG     Method: MCBLOCK Elapsed: 1.26276        MiB: 16.00000   Copy: 12.671 MiB/s