PCI: Remove redundant pci_dev, pci_bus, resource declarations

<linux/pci.h> defines struct pci_bus and struct pci_dev and includes the
struct resource definition before including <asm/pci.h>.  Nobody includes
<asm/pci.h> directly, so they don't need their own declarations.

Remove the redundant struct pci_dev, pci_bus, resource declarations.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Jesper Nilsson <jesper.nilsson@axis.com>	# CRIS
Acked-by: Ralf Baechle <ralf@linux-mips.org>		# MIPS