Update dell 3050 patch to patch 15 (pwm fix)

Use patchset 15 instead of 14:
config/coreboot/default/patches/0061-WIP-OptiPlex-3050-Micro-port.patch

Rebase the verb patch; patchset 15 modified the Makefile:
config/coreboot/default/patches/0064-dell-optiplex_3050-add-hda_verb.c.patch

We were using patchset 14 for the 3050 micro:
https://review.coreboot.org/c/coreboot/+/82053/14

Now we use patchset 15:
https://review.coreboot.org/c/coreboot/+/82053/15

Without this patch, the fans are always on a low setting, on
the Dell OptiPlex 3050 Micro, even under stress conditions. With
this patch, the fans change speed according to CPU temperature.

I had to rebase my verb patch, because Mate modified the Makefile
to add his sch5555 handler, on the same line where I add hda_verb.

Mate tells me he will merge my verb and vbt patches into a further
patchset later on. For now, I've simply rebased these patches on
top of Mate's newer work; I've told him he can use them in his port.

I'm probably going to now issue a new revision ROM image for
Libreboot 20241008, so that users can get this fix sooner.

Signed-off-by: Leah Rowe <leah@libreboot.org>

config/coreboot/default/patches/0028-HACK-Disable-coreboot-related-BL31-features.patch

@@ -1,7 +1,7 @@
-From ea6e8749112dee4f458e9cf591e13e9097d56bab Mon Sep 17 00:00:00 2001
+From 8fa72bedc6282ba581ede85d62a341917ec5d203 Mon Sep 17 00:00:00 2001
 From: Alper Nebi Yasak <alpernebiyasak@gmail.com>
 Date: Thu, 22 Jun 2023 16:44:27 +0300
-Subject: [PATCH 28/39] HACK: Disable coreboot related BL31 features
+Subject: [PATCH 28/65] HACK: Disable coreboot related BL31 features
 
 I don't know why, but removing this BL31 make argument lets gru-kevin
 power off properly when shut down from Linux. Needs investigation.
@@ -24,5 +24,5 @@ index cb43897efd..a9e5ff399a 100644
  BL31_MAKEARGS += BUILD_PLAT="$(BL31_BUILD)"
  
 -- 
-2.39.2
+2.39.5