x86/jailhouse: Allow to use PCI_MMCONFIG without ACPI

Jailhouse does not use ACPI, but it does support MMCONFIG. Make sure the
latter can be built without having to enable ACPI as well. Primarily, its
required to make the AMD mmconf-fam10h_64 depend upon MMCONFIG and
ACPI, instead of just the former.

Saves some bytes in the Jailhouse non-root kernel.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: jailhouse-dev@googlegroups.com
Cc: linux-pci@vger.kernel.org
Cc: virtualization@lists.linux-foundation.org
Cc: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Link: https://lkml.kernel.org/r/788bbd5325d1922235e9562c213057425fbc548c.1520408357.git.jan.kiszka@siemens.com