x86/PCI: Remove unused HyperTransport interrupt support

There are no in-tree callers of ht_create_irq(), the driver interface for
HyperTransport interrupts, left.  Remove the unused entry point and all the
supporting code.

See 8b955b0dddb3 ("[PATCH] Initial generic hypertransport interrupt
support").

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: linux-pci@vger.kernel.org
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Link: https://lkml.kernel.org/r/20171122221337.3877.23362.stgit@bhelgaas-glaptop.roam.corp.google.com
diff --git a/arch/x86/kernel/apic/vector.c b/arch/x86/kernel/apic/vector.c
index 05c85e6..6a823a2 100644
--- a/arch/x86/kernel/apic/vector.c
+++ b/arch/x86/kernel/apic/vector.c
@@ -1,5 +1,5 @@
 /*
- * Local APIC related interfaces to support IOAPIC, MSI, HT_IRQ etc.
+ * Local APIC related interfaces to support IOAPIC, MSI, etc.
  *
  * Copyright (C) 1997, 1998, 1999, 2000, 2009 Ingo Molnar, Hajnalka Szabo
  *	Moved from arch/x86/kernel/apic/io_apic.c.
@@ -601,7 +601,7 @@
 		nr_irqs = NR_VECTORS * nr_cpu_ids;
 
 	nr = (gsi_top + nr_legacy_irqs()) + 8 * nr_cpu_ids;
-#if defined(CONFIG_PCI_MSI) || defined(CONFIG_HT_IRQ)
+#if defined(CONFIG_PCI_MSI)
 	/*
 	 * for MSI and HT dyn irq
 	 */
@@ -663,7 +663,6 @@
 	irq_set_default_host(x86_vector_domain);
 
 	arch_init_msi_domain(x86_vector_domain);
-	arch_init_htirq_domain(x86_vector_domain);
 
 	BUG_ON(!alloc_cpumask_var(&vector_searchmask, GFP_KERNEL));