Add load base to map for relocation packing.

The new linker relocation packing support uses non-zero load bases,
so we better handle them properly.

Also print out the load base for a map if it's non-zero.

Bug: 20687795
(cherry picked from commit 329ed7da)

Change-Id: Ibc37d8c8bb032820dca4e7531184349ba6d402d2