Revert "mtd: hyperbus: hbmc-am654: Convert to platform remove callback returning void"

This reverts commit 784a7f4a which is
commit 59bd5676 upstream.

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

Bug: 161946584
Change-Id: Ic73e4b1884ba76869d637b3b2bc8eee50906a2d1
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>