driver-core: fix build for !CONFIG_MODULES

Commit f2411da74698 ("driver-core: add driver module asynchronous
probe support") broke build in case modules are disabled, because in this
case "struct module" is not defined and we can't dereference it. Let's
define module_requested_async_probing() helper and stub it out if modules
are disabled.

Change-Id: I707c72fd58ac5a480471ae693b569022e84ed3f0
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Git-commit: 80c6e1465948c2e91214f01764f427d31ebedb26
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git


Signed-off-by: Lingutla Chandrasekhar <clingutla@codeaurora.org>