Doc/releases: Fix coreboot 4.15 release notes

coreboot 4.15 has just been released, so it's neither "upcoming" nor
"planned" anymore.

Change-Id: I287e40deec5877764e511885e3268b606caff597
Signed-off-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/59121
Reviewed-by:  Felix Singer <felixsinger@posteo.net>
Reviewed-by: Jason Glenesk <jason.glenesk@amd.corp-partner.google.com>
Reviewed-by: Felix Held <felix-coreboot@felixheld.de>
Reviewed-by: Paul Menzel <paulepanter@mailbox.org>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

0 files changed, 0 insertions, 0 deletions