image_types_gbmc_dynamic: Fix add_partition_info_fitimage on multi DTB Fix the issue when using multiple DTB, the do_generated_static will failed to different FIT size because the sed changed to wrong dtb. Tested: Build on two different platforms, Both clean and append build Passed. Fusion-Link: https://fusion2.corp.google.com/6856b3c3-78a8-3435-902d-48352cbfaf31 https://fusion2.corp.google.com/c3ce8373-14f2-3023-aeeb-cc28062149b3 https://fusion2.corp.google.com/c83f7060-620e-3a74-bc10-e5a917b0e179 https://fusion2.corp.google.com/f12b3a24-985a-3db2-9f5e-a64c10202bfd Google-Bug-Id: 435560558 Change-Id: Ic2b0b456aef3e52a022a9858510284f8cf2da1d0 Signed-off-by: Steven Cho <cho.steven@inventec.corp-partner.google.com>