[SCSI] csiostor: Retain default adapter configuration in absence of config file.

- Retain firmware defined configuration settings in the absence of
user-provided configuration by eliminating the global RSS and the
PF/VF capabilities mailbox commands.
- Remove S_IRUGO from sysfs parameters that don't have 'show'
functionality.

Signed-off-by: Naresh Kumar Inna <naresh@chelsio.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>