sources.list: include the new non-free-firmware component

Debian (starting from bookworm) has pulled the firmware into a separate
component, non-free-firmware. Follow the move and include this component
into sources.list file.

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Change-Id: I9777e3ebfa52bd8094efc0a0d0eaf8da5893b097
diff --git a/files/etc/apt/sources.list/SID b/files/etc/apt/sources.list/SID
index 6d020d7..d126780 100644
--- a/files/etc/apt/sources.list/SID
+++ b/files/etc/apt/sources.list/SID
@@ -1,2 +1,2 @@
-deb {%apt_cdn%}/debian {%release%} main contrib non-free
-deb-src {%apt_cdn%}/debian {%release%} main contrib non-free
+deb {%apt_cdn%}/debian {%release%} main contrib non-free non-free-firmware
+deb-src {%apt_cdn%}/debian {%release%} main contrib non-free non-free-firmware