Add support for handling this concept in bootflows. Update the 'bootflow'
command to allow only the normal bootmeths to be used. This alllows
skipping EFI bootmgr and VBE, for example.
Signed-off-by: Simon Glass <sjg@chromium.org>
A bootflow encapsulates the process used to boot an operating system.
It typically has a control file (such as extlinux.conf) and information
about which 'bootdev' it came from.
Add the header file for this first, since it is needed by all other
files.
Signed-off-by: Simon Glass <sjg@chromium.org>