Please merge flash-kernel (main) 3.90 from Debian unstable (main)

I've uploaded a test version of the merged package here:

https://code.launchpad.net/~rbalint/+git/flash-kernel-merge/+ref/ubuntu/devel

This bug was fixed in the package flash-kernel - 3.90ubuntu1

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flash-kernel (3.90ubuntu1) bionic; urgency=medium

  [ Balint Reczey ]
  * Merge with Debian (LP: #1743771)
     - remaining changes:
       - add "quiet splash" as default options to omap bootscr
       - re-add support for the FLASH_KERNEL_SKIP env variable, so the image
         build infrastructure has a chance to skip the automated flash-kernel
         run during image builds.
       - bootscr.highbank: allow more space to load larger kernels
       - Add support for Calxeda Highbank (with bootscr.highbank different from
         Debian's version)
       - Re-add support for Marvell ArmadaXP
       - Fix armadaxp kernel load address
       - use umount -l in the cleanup function, else we fail while finishing up
         with the script
       - add DB entry for "OMAP3 Beagle Board" (funnily thats missing)
       - add Panda to the list of supported board in the README file
       - debian/control: Re-add omap and omap4 to the flash-kernel-installer
         XB-Subarchitecture field. These appear to have been lost somewhere
         along the way.
       - Also add omap and omap4 to flash-kernel-installer.isinstallable.
       - add a diversion for update-initramfs to live-installers
         post-base-installer.d to avoid update-initramfs runs before
         flash-kernel is configured
       - add a check for the diverted update-initramfs to
         flash-kernel-installer, so it gets reverted before we try to call
         update-initramfs
       - make post-base-installer.d/01flash-kernel-diversion actually an
         executable shell script
       - switch omap3 and omap4 to uEnv.txt/preEnv.txt (the former holds all
         active boot commands, the latter holds the kernel commandline only)
       - enable UUID detection of the currently used root device
       - if uEnv.txt is defined in the db for an arch, generate preEnv.txt from
         UBOOT_DEFAULTS and UUID detection data
       - switch omap3 and omap4 from Bootloader-sets-root: no to yes, we now
         generate a root=UUID= line on the fly for arches using
         uEnv.txt/preEnv.txt
       - introduce bootscript/uEnvtxt.omap
       - do not move the original uEnvtxt.omap to the target, use a copy instead
       - initramfs-tools/hooks/flash_kernel_set_root:
         - make sure that if we dont want to override the bootloader root=
           option by setting "Bootloader-sets-root: yes", we actually dont do it
         - Also check for FLASH_KERNEL_SKIP to avoid setting up the root
           parameter in case flash-kernel will not be used
         - this is a slightly different approach to fix the bug than
           the patch attached to the bug.
       - hide the boot device from udisk's automounting after installation
         on all systems using uEnv.txt to configure u-boot
       - make sure we only rename the bootrom partition so udisks hides it,
         when using mkdosfs for setting the label like we did in jasper (where
         we cached the contents before doing this) MLO and u-boot.bin are gone
       - make sure that /dev is bind mounted in /target when running
         upd...