Add a driver for the DS3232 RTC chip via the I2C bus.  Alarms are not
supported in this version of the driver.

[akpm@linux-foundation.org: fix Kconfig help text]
Signed-off-by: NMingkai Hu <Mingkai.hu@freescale.com>
Signed-off-by: NJingchang Lu <b22599@freescale.com>
Signed-off-by: NSrikanth Srinivasan <srikanth.srinivasan@freescale.com>
Signed-off-by: NRoy Zang <tie-fei.zang@freescale.com>
Acked-by: NWan ZongShun <mcuos.com@gmail.com>
Cc: Kumar Gala <kumar.gala@freescale.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>