Add option to specify HBDIR
Add option to specify HBDIR

This will be used to check HWP versions in fsp sandboxes.

Change-Id: Id6af5817a8506e262f1f59830191c759f805800f
RTC: 73596
Reviewed-on: http://gfw160.austin.ibm.com:8080/gerrit/5066
Tested-by: Jenkins Server
Reviewed-by: Brian H. Horton <4d3586b959590a6e034649b5cc7435fb7d9ba30c@linux.ibm.com>
Reviewed-by: A. Patrick Williams III <c87e37b1a4035affd737b461af89fb722d635f4d@us.ibm.com>

csmart/hostboot,open-power/hostboot,alvintpwang/hostboot,Over-enthusiastic/hostboot,Over-enthusiastic/hostboot,Over-enthusiastic/hostboot,alvintpwang/hostboot,alvintpwang/hostboot,csmart/hostboot,open-power/hostboot,Over-enthusiastic/hostboot,open-power/hostboot,csmart/hostboot,open-power/hostboot,csmart/hostboot,open-power/hostboot,Over-enthusiastic/hostboot,alvintpwang/hostboot,csmart/hostboot,alvintpwang/hostboot