mptfusion: mark file-private functions as static

Fixes the following sparse warnings:

  drivers/message/fusion/mptbase.c:7011:1: warning: symbol
    'mpt_SoftResetHandler' was not declared. Should it be static?

  drivers/message/fusion/mptsas.c:1578:23: warning: symbol
    'mptsas_refreshing_device_handles' was not declared. Should it be
    static?

  drivers/message/fusion/mptsas.c:3653:24: warning: symbol
    'mptsas_expander_add' was not declared. Should it be static?

  drivers/message/fusion/mptsas.c:5327:1: warning: symbol
    'mptsas_shutdown' was not declared. Should it be static?

  drivers/message/fusion/mptspi.c:624:1: warning: symbol
    'mptscsih_quiesce_raid' was not declared. Should it be static?

Signed-off-by: Joe Lawrence <joe.lawrence@stratus.com>
Acked-by: Sreekanth Reddy <Sreekanth.Reddy@avagotech.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>