drivers/rtc/rtc-tegra.c: clean up probe/remove routines

Use the devres managed resource functions in the probe routine.  Also
affects the remove routine where the previously used free and release
functions are not needed.

The devm_* functions eliminate the need for manual resource releasing and
simplify error handling.  Resources allocated by devm_* are freed
automatically on driver detach.

Signed-off-by: Hannu Heikkinen <ext-hannu.m.heikkinen@nokia.com>
Acked-by: Stephen Warren <swarren@wwwdotorg.org>
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>