x86: qemu: Implement PIRQ routing

Support QEMU PIRQ routing via device tree on both i440fx and q35
platforms. With this commit, Linux booting on QEMU from U-Boot
has working ATA/SATA, USB and ethernet.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Acked-by: Simon Glass <sjg@chromium.org>
diff --git a/include/configs/qemu-x86.h b/include/configs/qemu-x86.h
index d01936b..78c296f 100644
--- a/include/configs/qemu-x86.h
+++ b/include/configs/qemu-x86.h
@@ -14,6 +14,7 @@
 #include <configs/x86-common.h>
 
 #define CONFIG_SYS_MONITOR_LEN		(1 << 20)
+#define CONFIG_ARCH_MISC_INIT
 
 #define CONFIG_X86_SERIAL