rtc-pcf2123: move pcf2123_remove to .devexit.text

The function pcf2123_remove is used only wrapped by __devexit_p so define
it using __devexit.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Alessandro Zummo <a.zummo@towertech.it>
Cc: Christian Pellegrin <chripell@fsfe.org>
Cc: Chris Verges <chrisv@cyberswitching.com>
Cc: Paul Gortmaker <p_gortmaker@yahoo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>