Revert "pwm: atmel-hlcdc: Convert to platform remove callback returning void"

This reverts commit 81f0b319 which is
commit 5fce9417 upstream.

It breaks the Android kernel build and can be brought back in the future
in an abi-safe way if it is really needed.

Bug: 161946584
Change-Id: I98bdae465bdbb52dad7b172899cc8fad81d6cfcd
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>