pseries: Update SLOF firmware image

This adds TPM pass through API.
Also, moves SLOF from github to gitlab.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>

pc-bios/README

@@ -13,8 +13,8 @@
 
 - SLOF (Slimline Open Firmware) is a free IEEE 1275 Open Firmware
   implementation for certain IBM POWER hardware.  The sources are at
-  https://github.com/aik/SLOF, and the image currently in qemu is
-  built from git tag qemu-slof-20230918.
+  https://gitlab.com/slof/slof, and the image currently in qemu is
+  built from git tag qemu-slof-20241106.
 
 - VOF (Virtual Open Firmware) is a minimalistic firmware to work with
   -machine pseries,x-vof=on. When enabled, the firmware acts as a slim shim and