driver core: fix possible missing of device probe

Inside bus_add_driver(), one device might be added(device_add()) into
the bus or probed which is triggered by deferred probe
just after completing of driver_attach() and before
'klist_add_tail(&priv->knode_bus, &bus->p->klist_drivers)',
so the device won't be probed by this driver.

This patch moves the below line

	'klist_add_tail(&priv->knode_bus, &bus->p->klist_drivers)'

before driver_attach() inside bus_add_driver() to fix the
problem.

CRs-Fixed: 588802
Change-Id: I9250b399d57a89870d1df220b97fdca275e2e1a9
Signed-off-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Git-commit: 190888ac
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git


Signed-off-by: Sagar Dharia <sdharia@codeaurora.org>
Signed-off-by: Swetha Chikkaboraiah <schikk@codeaurora.org>