K 10
svn:author
V 5
lwhsu
K 8
svn:date
V 27
2022-02-02T14:25:28.447845Z
K 7
svn:log
V 472
mkimg: Add support for offset if the source is an image

This allow us to create image with the following format:
mkimg -v -o sdcard -s gpt -p efi:=esp_aarch64.img:1M -p freebsd-ufs::1G

Which will add a efi partition at a 1M offset on the image with its content
coming from the esp_aarch64.img file.

MFC after:	3 days

(cherry picked from commit 8f3c71c85e5f6a4d2bddbfead225d33b96dbd7d7)

Git Hash:   51f120a810427b802c46686350fff0f30a145633
Git Author: manu@FreeBSD.org
END