readline: apply missing upstream patches

readline: apply missing upstream patches

Some readline-6.3 upstream patches was missing. Also ensure that the
upstream patches are applied in the same way as in readline-5.2.

Remove 'readline-dispatch-multikey.patch' and
'readline-cve-2014-2524.patch' since they are already included in
upstream patches 'readline63-002' and 'readline63-003'.

[YOCTO #8451]

Signed-off-by: Petter Mabäcker <petter@technux.se>
Signed-off-by: Ross Burton <ross.burton@intel.com>