RTC v3020 fixes

Fix off-by-one in month calculations
Add delay for bus accesses to satisfy Tw > 500ns

Signed-off-by: Mike Rapoport <mike@compulab.co.il>
Acked-by: Raphael Assenat <raph@8d.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>