fix lpc2000 flash programming fail.

fix lpc2000 flash programming fail.

 some members of lpc2000_info structure sometimes used uninitialized
 (cmd51_can_64b for all LPC except LPC800 as example).
  Init allocated lpc2000_info structure with zeros to avoid this and similar bugs in the future.
  Note: maybe discarding all cmd51_can_XXXb fields and using cmd51_dst_boundary instead will be a better solution.

Signed-off-by: Sergey A. Borshch <sb-sf@users.sourceforge.net>
Change-Id: Idf116a5b0bf4ea1c39ea0ce308ec2c13bfbd4d8c
Reviewed-on: http://openocd.zylin.com/1676
Tested-by: jenkins
Reviewed-by: Andreas Fritiofson <andreas.fritiofson@gmail.com>
Reviewed-by: Nemui Trinomius <nemuisan_kawausogasuki@live.jp>