[SCSI] megaraid_legacy: removed PCI ID overlap from the driv er

This patch fixes
	- PCI ID overlap issue
	- node name changed to 'megaraid_legacy'
I hope this patch addresses concerns brought by Daniel Drake.

Signed-off by: Seokmann Ju <seokmann.ju@enginio.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>