1.26 is the stable and recommended firmware for Skylake.
However one conflict in i915 accidentally restored 1.23
making that the default in some kernel out there.

So, let's restore this 1.23 here.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=97182


Cc: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>