generate_boot_bins.sh: add support for efiesp generation

[Ananthu C V (WeepingClown13)]

efiesp.bin is used in WP meta as the EFI that contains kernel image, ramfs, and dtb. We need a way to generate this during kernelci pipeline for enabling upstream testing on devices running WP meta, which the new efiesp command does. The new addition breaks down to this;

efiesp command options:
  --ramdisk PATH         Path to the ramdisk file
  --linux PATH           Path to the Linux Image
  --devicetree PATH      Path to the DTB file
  --cmdline CMDLINE      Kernel command line parameters
  --systemd-boot PATH    Path to the systemd boot binary

it takes a few mandatory params and generates and efiesp of size 260MiB, as per WP meta expectations. The reason for this size hardcoding is documented alongside the efi generation.

This change will require a new version of the docker image to be released to the registry, so that required consumers can point to the new version of the image to use this utility.

[Ananthu C V (WeepingClown13)]

Komal Bajaj (@Komal-Bajaj) Yogesh Lal (@yogeshlal) please have a look. We need this change to be enabled to get kernelci going for WP meta running devices. It does not change anything existing, so there is no breakage, it just adds a new efiesp command option.