qemu-linuxboot: ASSERT error when running linuxboot.rom in QEMU

Nobody has claimed this yet.

I get the following ASSERT error when trying to run qemu-linuxboot built using HEADS with kernel version 4.14.62:

```
[...]
+--------------------+
| |
| Starting LinuxBoot |
| |
+--------------------+
num tables=0005
49AA7D31FC1BCDB0
42146F0205AD34BA
FvLoader: adding firmware volume 0xFF500000
FvLoader: error rc=0000000A
0000000000000000
0000000000000000
0000000000000000
0000000000000000
0000000000000000
0000000000000000
0000000000000000
0000000000000000
0000000000000000
0000000000000000
0000000000000000
0000000000000000
0000000000000000
0000000000000000
0000000000000000
0000000000000000
InstallProtocolInterface: 665E3FF6-46CC-11D4-9A38-0090273FC14D 7B2E408
LinuxBoot: waiting for BDS callback
[...]
--------
Transfering control to BDS 7B2E408
Entry Point 7B2C280 (7B2C280)
--------
LinuxBoot: BDS time has arrived
LinuxBoot: connect pci root brdiges
efi_visit_handles 2F707EBB
handle_count=00000001
PCI Bus First Scanning
PciBus: Discovered PCI @ [00|00|00]

PciBus: Discovered PCI @ [00|01|00]
BAR[0]: Type = PMem32; Alignment = 0xFFFFFF; Length = 0x1000000; Offset = 0x10
BAR[2]: Type = Mem32; Alignment = 0xFFF; Length = 0x1000; Offset = 0x18

PciBus: Discovered PCI @ [00|02|00]
ASSERT [PciHostBridgeDxe] /linuxboot/edk2/MdePkg/Library/BasePciCf8Lib/PciCf8Lib.c(1114): ((Address) & (~0xffff0ff | (3))) == 0
```

It also occurs when running `make BOARD=qemu` in the LinuxBoot project itself and using the bzImage and initrd artifacts from the HEADS build.

It looks like the assertion is made during the call to `gBS->ConnectController()` in `efi_connect_controllers()` on line 170 of dxe/linuxboot.c

Has anyone else run into this problem before?

Reproduce with `make BOARD=qemu` using the HEADS bzImage and initrd artifacts, then start at `edk2/MdePkg/Library/BasePciCf8Lib/PciCf8Lib.c:1114` and the `gBS->ConnectController()` call in `dxe/linuxboot.c:170`. Trace the PCI controller connection that triggers the assertion and verify that the qemu-linuxboot path completes without it.

Written by the indexing model from the issue text.