opie-pics: use MACHINE_GUI_CLASS instead of older GUI_MACHINE_CLASS
opie-pics: use MACHINE_GUI_CLASS instead of older GUI_MACHINE_CLASS

meta-handheld made this switch a while ago.

Signed-off-by: Paul Eggleton <737d4dae46a541673d7bf4e0d5b32714b16528d8@linux.intel.com>

bluelightning/meta-opie,bluelightning/meta-opie,bluelightning/meta-opie,bluelightning/meta-opie,bluelightning/meta-opie