Re-installation of device-tree as EFI configuration table

[Sughosh Ganu]

hi,
The logic in efi_install_fdt() is such that with the
EFI_FDT_USE_INTERNAL passed as a parameter to the function, the EFI
configuration table is first checked to see if a device-tree(DT) has
already been installed as the configuration table, and in case a table
is found, the function returns without any other changes. However,
there might be scenarios where the earlier installed configuration
table might not be up-to-date, and in need of modification. One such
scenario is that of adding a pmem node to the DT that is to be passed
on to the OS. There could thus be a scenario where a DT that is
installed as a configuration table does not have the pmem node, or it
might have the wrong/stale values for the pmem node. Should there be
some logic to indicate that the configuration table needs to be
re-installed afresh so that these scenarios can be handled. Thoughts?

-sughosh