Move function declarations to megaraid_sas.h to avoid warnings such as:

	warning: no previous prototype for ‘xxx'

No functional changes.

Link: https://lore.kernel.org/r/20200706123346.451827-1-damien.lemoal@wdc.com


Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>