P9-XIP: ekb build flow integration
P9-XIP: ekb build flow integration

The P9-XIP API code and the p9_xip_tool are now build by the overall
ekb build flow. Run "ekb build p9_xip_tool" to only build the code
in chips/p9/xip.

Both p9_ring_identification and p9_xip_image are now created as
objects that can be linked by anyone in ekb who needs this code.

Change-Id: I2d5c3cfed358ff999a09ae35f36aaeb3f3f47504
Reviewed-on: http://gfw160.aus.stglabs.ibm.com:8080/gerrit/23680
Tested-by: Jenkins Server
Reviewed-by: Claus Michael Olsen <2da381e13dc4aeb07a557ddfc89fbb05265c54a4@us.ibm.com>
Reviewed-by: PRACHI GUPTA <25a72946fc4ec2539bba3cff1fbb2916af6a7649@us.ibm.com>
Reviewed-by: Martin Peschke <4c516a35580133f593dfe866810ac6bfbd5b0dba@de.ibm.com>
Reviewed-on: http://gfw160.aus.stglabs.ibm.com:8080/gerrit/24285
Reviewed-by: Daniel M. Crowell <912029ca9254ac7b5854e56910561d682e1fa2d0@us.ibm.com>

Over-enthusiastic/hostboot,Over-enthusiastic/hostboot,Over-enthusiastic/hostboot,Over-enthusiastic/hostboot,Over-enthusiastic/hostboot