Revert "ARM: amba: Fix race condition with driver_override"

This reverts commit 6b614a87.

My backport was incorrect, as Geert pointed out :(

Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Todd Kjos <tkjos@google.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>