The commit 25635c71e441 ("ppc: Use the indirect_pci.c from arch/powerpc/sysdev")
introduced PPC_INDIRECT_PCI as a non-visible config that depends on PCI. 

Since it is non-visible, the dependency on PCI has no implications other
than leading to Kbuild build warnings if !PCI. For example, disabling PCI
and enabling LINKSTATION leads to the following Kbuild warning since
PPC_INDIRECT_PCI is selected by MPC10X_BRIDGE, which is selected by
LINKSTATION:

WARNING: unmet direct dependencies detected for PPC_INDIRECT_PCI
  Depends on [n]: PCI [=n]
  Selected by [y]:
  - MPC10X_BRIDGE [=y]

There are many other configs that select PPC_INDIRECT_PCI but they seem
to enable PCI one way or another, e.g., enabling FORCE_PCI or selecting
PPC_INDIRECT_PCI if PCI. Among them, only MPC10X_BRIDGE and MV64X60 seem
to not account for the dependency on PCI, and MV64X60 seem to be obsolete:
https://bugzilla.kernel.org/show_bug.cgi?id=209277

I am not sure about the internals of the user subsystem. However, two fix
options I see are: 1) --select FORCE_PCI-- by MPC10X_BRIDGE, 2) select
PPC_INDIRECT_PCI --if PCI-- by MPC10X_BRIDGE.

Thanks,
Necip