Support MinnowBoard MAX

To configure for MinnowBoard MAX, use 'intel-corei7-64' as MACHINE.

E.g. set up build environment by meta-agl's script:
  $ source meta-agl/script/envsetup.sh intel-corei7-64 [build-dir]

There are instructions to write image into SD card and boot system
at "http://elinux.org/Minnowboard:MinnowMaxYoctoProject".

Change-Id: I19062482848bb6157791ab698bf92984e24a6d9a
Signed-off-by: Tadao Tanikawa <tanikawa.tadao@jp.panasonic.com>