x86: Refactor PIRQ routing support

PIRQ routing is pretty much common in Intel chipset. It has several
PIRQ links (normally 8) and corresponding registers (either in PCI
configuration space or memory-mapped IBASE) to configure the legacy
8259 IRQ vector mapping. Refactor current Queensbay PIRQ routing
support using device tree and move it to a common place, so that we
can easily add PIRQ routing support on a new platform.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Acked-by: Simon Glass <sjg@chromium.org>
diff --git a/arch/x86/cpu/queensbay/Makefile b/arch/x86/cpu/queensbay/Makefile
index 4599a48..d8761fd 100644
--- a/arch/x86/cpu/queensbay/Makefile
+++ b/arch/x86/cpu/queensbay/Makefile
@@ -5,5 +5,5 @@
 #
 
 obj-y += fsp_configs.o
-obj-y += irq.o tnc.o topcliff.o
+obj-y += tnc.o topcliff.o
 obj-$(CONFIG_PCI) += tnc_pci.o