x86, pci: move arch/x86/pci/pci.h to arch/x86/include/asm/pci_x86.h

Impact: cleanup

Now that arch/x86/pci/pci.h is used in a number of other places as well,
move the lowlevel x86 pci definitions into the architecture include files.
(not to be confused with the existing arch/x86/include/asm/pci.h file,
which provides public details about x86 PCI)

Tested on: X86_32_UP, X86_32_SMP and X86_64_SMP

Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
Acked-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>