soc/amd: introduce and use common amd_cpu_bus_ops struct

The device operations for the CPU bus are identical for all AMD SoCs, so
introduce a common device operations struct for this and use it in all
AMD SoC's chipset devicetrees as ops for the CPU cluster.

Signed-off-by: Felix Held <felix-coreboot@felixheld.de>
Change-Id: Id32f89b8a33db8dbb747b917eeac3009fbae6631
Reviewed-on: https://review.coreboot.org/c/coreboot/+/71998
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Elyes Haouas <ehaouas@noos.fr>
Reviewed-by: Fred Reitberger <reitbergerfred@gmail.com>
diff --git a/src/soc/amd/stoneyridge/chipset_st.cb b/src/soc/amd/stoneyridge/chipset_st.cb
index 4c244d0..c78da61 100644
--- a/src/soc/amd/stoneyridge/chipset_st.cb
+++ b/src/soc/amd/stoneyridge/chipset_st.cb
@@ -2,7 +2,7 @@
 
 chip soc/amd/stoneyridge
 	device cpu_cluster 0 on
-		ops stoneyridge_cpu_bus_ops
+		ops amd_cpu_bus_ops
 	end
 	device domain 0 on
 		ops stoneyridge_pci_domain_ops