coreboot/fam15h: use 4.11_branch (fixes build)

This fixes build errors on KGPE-D16.

I can now build them on the latest Debian Sid,
as of 9 July 2023.

Signed-off-by: Leah Rowe <leah@libreboot.org>

resources/coreboot/fam15h_rdimm/board.cfg

 cbtree="fam15h_rdimm"
 romtype="normal"
-cbrevision="ad983eeec76ecdb2aff4fb47baeee95ade012225"
+cbrevision="1c13f8d85c7306213cd525308ee8973e5663a3f8"
 arch="x86_64"
 payload_grub="n"
 payload_grub_withseabios="n"

resources/coreboot/fam15h_udimm/board.cfg

 cbtree="fam15h_udimm"
 romtype="normal"
-cbrevision="ad983eeec76ecdb2aff4fb47baeee95ade012225"
+cbrevision="1c13f8d85c7306213cd525308ee8973e5663a3f8"
 arch="x86_64"
 payload_grub="n"
 payload_grub_withseabios="n"