- Correct a typo "mvram" -> "nvram".
 - Re-do the PQS/PDS support which I'd #if 0 out.  Should even work on
   multiple-domain boxes now ;-)
 - Move all the nvram definitions to sym_nvram.h (from Gerard's 2.1.19-pre3)
 - hcb_p -> struct sym_hcb *
 - sdev_p -> struct sym_device *
 - Delete a lot of unused macros from sym_misc.h
 - Move READ_BARRIER and WRITE_BARRIER definitions to sym_glue.h
 - SYM_CONF_NVRAM_WRITE_SUPPORT (from Gerard's 2.1.19-pre3).  Not enabled
   yet.
 - Fix some -W warnings (some courtesy of Adrian Bunk).