include/device/pci_ids,soc/amd/common/block/lpc: drop duplicate PCI IDs

PCI_DEVICE_ID_AMD_FAM17H_LPC and PCI_DEVICE_ID_AMD_FAM17H_SMBUS redefine
the same values that are already defined by PCI_DEVICE_ID_AMD_CZ_LPC and
PCI_DEVICE_ID_AMD_CZ_SMBUS, so drop PCI_DEVICE_ID_AMD_FAM17H_LPC and
PCI_DEVICE_ID_AMD_FAM17H_SMBUS. Also add some comments to the places in
the code where the defines are used to clarify which ID is used on which
hardware generation.

Signed-off-by: Felix Held <felix-coreboot@felixheld.de>
Change-Id: Id0b3d7b5a886ccc76d82ada6be4145e85fd51ede
Reviewed-on: https://review.coreboot.org/c/coreboot/+/58696
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Jason Glenesk <jason.glenesk@gmail.com>
Reviewed-by: Raul Rangel <rrangel@chromium.org>
diff --git a/src/southbridge/amd/pi/hudson/lpc.c b/src/southbridge/amd/pi/hudson/lpc.c
index 77d39c5..784147c 100644
--- a/src/southbridge/amd/pi/hudson/lpc.c
+++ b/src/southbridge/amd/pi/hudson/lpc.c
@@ -354,7 +354,9 @@
 };
 
 static const unsigned short pci_device_ids[] = {
+	/* PCI device ID is used on all discrete FCHs and Family 16h Models 00h-3Fh */
 	PCI_DEVICE_ID_AMD_SB900_LPC,
+	/* PCI device ID is used on all integrated FCHs except Family 16h Models 00h-3Fh */
 	PCI_DEVICE_ID_AMD_CZ_LPC,
 	0
 };