ipmi:pci: Blacklist a Realtek "IPMI" device

commit bc48fa1b9d3b04106055b27078da824cd209865a upstream.

Realtek has some sort of "Virtual" IPMI device on the PCI bus as a
KCS controller, but whatever it is, it's not one.  Ignore it if seen.

[ Commit 13d0b35c (ipmi_si: Move PCI setup to another file) from Linux
  4.15-rc1 has not been back ported, so the PCI code is still in
  `drivers/char/ipmi/ipmi_si_intf.c`, requiring to apply the commit
  manually.

  This fixes a 100 s boot delay on the HP EliteDesk 705 G4 MT with Linux
  4.14.94. ]

Reported-by: Chris Chiu <chiu@endlessm.com>
Signed-off-by: Corey Minyard <cminyard@mvista.com>
Tested-by: Daniel Drake <drake@endlessm.com>
Signed-off-by: Paul Menzel <pmenzel@molgen.mpg.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>