[SCSI] Merge sym53c8xx_comm.h and sym53c8xx_defs.h into ncr driver

When the sym1 driver was in the tree, it used to share various parts of
its infrastructure with the ncr driver.  Now it's gone, these files are
just an annoyance, so merge sym53c8xx_comm.h into ncr53c8xx.c and merge
sym53c8xx_defs.h into ncr53c8xx.h.

Signed-off-by: Matthew Wilcox <matthew@wil.cx>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>