x86: qemu: Make host bridge (b.d.f=0.0.0) visible

The default weak version of pci_skip_dev() in drivers/pci/pci_common.c
skips the host bridge (b.d.f = 0.0.0) which is actually the i440fx/q35
chipset for QEMU targets. Define CONFIG_PCI_CONFIG_HOST_BRIDGE to make
it visible in the PCI configuration space.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Acked-by: Simon Glass <sjg@chromium.org>

include/configs/qemu-x86.h

@@ -29,6 +29,7 @@
 #define CONFIG_PCI_IO_PHYS		CONFIG_PCI_IO_BUS
 #define CONFIG_PCI_IO_SIZE		0xe000
 
+#define CONFIG_PCI_CONFIG_HOST_BRIDGE
 #define CONFIG_PCI_PNP
 #define CONFIG_E1000
 

include/configs/x86-common.h

@@ -244,6 +244,7 @@
 
 #define CONFIG_EXTRA_ENV_SETTINGS			\
 	CONFIG_STD_DEVICES_SETTINGS			\
+	"pciconfighost=1\0"				\
 	"netdev=eth0\0"					\
 	"consoledev=ttyS0\0"				\
 	"othbootargs=acpi=off\0"			\