x86_64: add dmidecode utility

Reviewed By: puneet, dustin

This patch adds the 'dmidecode' utility from the dmidecode project to
x86_64 platforms.

See:  http://www.nongnu.org/dmidecode/

Testing Done:

Built an image and loaded on a x86_64 based platform.  Exercised the
dmidecode command.  The output looks reasonable.