14.0 relnotes: fixups to previous revision

Two fixes to last revision of this file: fix and clarify section on
upgrading loader.efi, rearranging so as to reference the example
efibootmgr output in determining the ESP partition, and remove the
"noauto" possibility. One of my mutiply-upgraded systems has the
noauto line in fstab, but I could have added it myself. Also, add
more specific information about iwlwifi chipset support from bz.