readline: update to 8.0 (patchlevel 1)

readline: update to 8.0 (patchlevel 1)

The third version of this patch fixes missing rootfile changes, drops
orphaned readline 5.2 patches (as they became obsolete due to
readline-compat changes), includes readline 8.0 upstream patch, and
keeps the for-loop in LFS file (as commented by Michael).

Cc: Michael Tremer <michael.tremer@ipfire.org>
Cc: Arne Fitzenreiter <arne_f@ipfire.org>
Signed-off-by: Peter Müller <peter.mueller@ipfire.org>
Signed-off-by: Arne Fitzenreiter <arne_f@ipfire.org>