iwmfw(4): fix spelling of the iwm8000C firmware.

When migrating the firmware to be installed as plain firmware files
to /boot/firmware the iwm8000C firmware lost its "fw" suffix that
iwm(4) expects.
The follow-up change to defaults/loader.conf is also consistently
missing the "fw".

Fix both places, and add the wrongly spelt version to ObsoleteFiles.inc
(entirely untested).

PR:		291403
Reported by:	Augustin Hoffmann (avgwst tutanota.de)
Fixes:		af0a81b647
Fixes:		a0f06dfb0d
MFC after:	3 days

ObsoleteFiles.inc

@@ -51,6 +51,9 @@
 #   xargs -n1 | sort | uniq -d;
 # done
 
+# 20251208: Rename iwm8000C to correct name.
+OLD_FILES+=boot/firmware/iwm8000C
+
 # 20251207: removed libuutil and libtpool
 OLD_LIBS+=	lib/libuutil.so.2
 OLD_LIBS+=	lib/libtpool.so.2

share/firmwares/iwm/Makefile

@@ -41,7 +41,7 @@ iwm7265DMODE=	644
 iwm7265DPACKAGE=	firmware-iwm
 
 iwm8000C=	${SRCTOP}/sys/contrib/dev/iwm/iwm-8000C-22.fw
-iwm8000CNAME=	iwm8000C
+iwm8000CNAME=	iwm8000Cfw
 iwm8000CDIR=	/boot/firmware
 iwm8000CMODE=	644
 iwm8000CPACKAGE=	firmware-iwm

stand/defaults/loader.conf

@@ -195,5 +195,5 @@ iwm8265fw_type="firmware"
 iwm9260fw_type="firmware"
 iwm3168fw_type="firmware"
 iwm7265Dfw_type="firmware"
-iwm8000C_type="firmware"
+iwm8000Cfw_type="firmware"
 iwm9000fw_type="firmware"