3rdparty/libgfxinit: Update submodule pointer

This brings in LSPCON support.

Change-Id: I35cefa2aa8107b7841d7cf7a7bb61d4b591d14ae
Signed-off-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/51147
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-by: Matt DeVillier <matt.devillier@gmail.com>

3rdparty/libgfxinit

@@ -1 +1 @@
-Subproject commit bc0588e482b1320d5739900b00a45033f5b587f4
+Subproject commit 8d5c24dddd04392e78578a41e574e15a487e3033