x86/PCI: Remove unused HyperTransport interrupt support

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 <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>
Acked-by: "Eric W. Biederman" <[email protected]>
Cc: Andi Kleen <[email protected]>
Cc: Greg Kroah-Hartman <[email protected]>
Cc: [email protected]
Cc: Benjamin Herrenschmidt <[email protected]>
Link: https://lkml.kernel.org/r/20171122221337.3877.23362.stgit@bhelgaas-glaptop.roam.corp.google.com