[SCSI] megaraid_sas: fix suspend/resume sections

megaraid_sas suspend and resume are inappropriatelly placed in
__devinit section. Remove those placements and make the stuff
dependent on CONFIG_PM.

While at it, mark remove function as __devexit.

Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Acked-by: "Yang, Bo" <Bo.Yang@lsi.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>