bitbake: bitbake/cookerdata: Explicitly specify cooker configuration options

bitbake: bitbake/cookerdata: Explicitly specify cooker configuration options

As the code stands today its hard to know which configuration variables
are used by which parts of the system. Some are used by the UIs, some
by bin/bitbake itself, some by cooker.

This patch changes the configuration to just contain the variables cooker
uses, and changes bin/bitbake to access the variables it needs directly
which hopefully lets us start to untangle this mess.

(Bitbake rev: e57497a24b6157c92519a34accd66035a39ad1f8)

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>