[SCSI] scsi_debug: remove scsi_debug.h

scsi_debug.h just incldues some function declarations. This patch removes it
with moving the scsi_host_template.

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Acked-by: Douglas Gilbert <dougg@torque.net>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>