[SCSI] megaraid: pci_module_init to pci_register_driver

Convert pci_module_init() to pci_register_driver().

Signed-off-by: Richard Knutsson <ricknu-0@student.ltu.se>
Acked-by: "Patro, Sumant" <Sumant.Patro@lsi.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>