Fix the following sparse warning:

drivers/scsi/megaraid/megaraid_sas_fp.c:88:5: warning: symbol
'mega_div64_32' was not declared. Should it be static?
drivers/scsi/megaraid/megaraid_sas_fp.c:370:5: warning: symbol
'MR_GetSpanBlock' was not declared. Should it be static?
drivers/scsi/megaraid/megaraid_sas_fp.c:420:5: warning: symbol
'mr_spanset_get_span_block' was not declared. Should it be static?
drivers/scsi/megaraid/megaraid_sas_fp.c:645:4: warning: symbol 'get_arm'
was not declared. Should it be static?
drivers/scsi/megaraid/megaraid_sas_fp.c:788:4: warning: symbol
'MR_GetPhyParams' was not declared. Should it be static?
drivers/scsi/megaraid/megaraid_sas_fp.c:1345:4: warning: symbol
'megasas_get_best_arm_pd' was not declared. Should it be static?

Link: https://lore.kernel.org/r/20200407092827.18074-3-yanaijie@huawei.comReported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Jason Yan <yanaijie@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>