yocto-bsp: prepend includes in machine.scc files with machine

The names of the -user files were changed to have the machine
prepended, but the includes weren't - fix the includes.

(From meta-yocto rev: f56d24c04f00cfb2671e3f097f221d636ebb7943)

Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
yocto-bsp: set branches_base for list_property_values()

yocto_bsp_list_property_values() is missing the context it needs to
properly filter choicelists, so add it to the context object.

Fixes [YOCTO #3233]

(From meta-yocto rev: 064b15f76c5b52899f4c3fdef06412c3063062a5)

(From meta-yocto rev: d381095eed24a426ea655c04279e23b13b1af34a)

Signed-off-by: Tom Zanussi <tom.zanussi@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>