Added clean & clobber targets
Added clean & clobber targets

Change-Id: Ia3dbc5798c039d02b6814724ba5818553139e257
Original-Change-Id: I4c86627ec942f389251ccbdb08a7e7e8a9da5565
RTC: 151009
Reviewed-on: http://ralgit01.raleigh.ibm.com/gerrit1/25684
Tested-by: Jenkins Server
Tested-by: Hostboot CI
Reviewed-by: Michael Baiocchi <a81f28e8886c5e2bd4bbd867228778c3b7b19dea@us.ibm.com>
Reviewed-by: Daniel M. Crowell <912029ca9254ac7b5854e56910561d682e1fa2d0@us.ibm.com>
Reviewed-by: William G. Hoffa <7dd6aa5e78423995d9d7c7ecada5b77ee07f88cc@us.ibm.com>

open-power/hostboot,open-power/hostboot,open-power/hostboot,open-power/hostboot,open-power/hostboot