Revert commit 2830a6d2.

We already perform the ida_simple_remove() in rtc_device_release(),
which is an appropriate place.  Commit 2830a6d2 ("rtc: recycle id when
unloading a rtc driver") caused the kernel to emit

	ida_remove called for id=0 which is not allocated.

warnings when rtc_device_release() tries to release an alread-released
ID.

Let's restore things to their previous state and then work out why
Vincent's kernel wasn't calling rtc_device_release() - presumably a bug
in a specific sub-driver.
Reported-by: Lothar Waßmann <LW@KARO-electronics.de>
Acked-by: Alexander Holler <holler@ahsoftware.de>
Cc: Vincent Palatin <vpalatin@chromium.org>
Cc: <stable@vger.kernel.org>		[3.7.x]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>