PCI: Remove redundant pcibios_set_master() declarations

All users of pcibios_set_master() include <linux/pci.h>, which already has
a declaration.  Remove the unnecessary declarations from the <asm/pci.h>
files.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
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