fsl_pci: Move prototypes into fsl_pci.h and remove explicit externs

board/atum8548/atum8548.c

board/freescale/mpc8536ds/mpc8536ds.c

board/freescale/mpc8544ds/mpc8544ds.c

board/freescale/mpc8548cds/mpc8548cds.c

board/freescale/mpc8568mds/mpc8568mds.c

board/freescale/mpc8569mds/mpc8569mds.c

board/freescale/mpc8572ds/mpc8572ds.c

board/freescale/mpc8610hpcd/mpc8610hpcd.c

board/freescale/mpc8641hpcn/mpc8641hpcn.c

board/sbc8548/sbc8548.c

board/sbc8641d/sbc8641d.c

board/tqc/tqm85xx/tqm85xx.c

board/xes/common/fsl_85xx_pci.c

include/asm-ppc/fsl_pci.h