drivers/rtc/rtc-imxdi.c: add more known register bits

Intended for monitoring and controlling the security features.  These bits
are required to bring this unit back to live after a security violation
event was detected.  The code to bring it back to live will follow after a
vendor clearance.

Signed-off-by: Juergen Borleis <jbe@pengutronix.de>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>