Drivers: hv: vmbus: Don't wait for the ACPI device upon initialization

Waiting to 5 seconds in case of missing VMBus ACPI device is redundant as the
device is either present already or won't be available at all.

This patch enforces synchronous probing to make sure the bus traversal,
happening upon driver registering will either find the device (if present) or
not spend any additional time if device is absent.

Signed-off-by: Stanislav Kinsburskiy <stanislav.kinsburskiy@gmail.com>
CC: "K. Y. Srinivasan" <kys@microsoft.com>
CC: Haiyang Zhang <haiyangz@microsoft.com>
CC: Stephen Hemminger <sthemmin@microsoft.com>
CC: Wei Liu <wei.liu@kernel.org>
CC: Dexuan Cui <decui@microsoft.com>
CC: linux-hyperv@vger.kernel.org
CC: linux-kernel@vger.kernel.org
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Reviewed-by: Dexuan Cui <decui@microsoft.com>
Link: https://lore.kernel.org/r/166378554568.581670.1124852716698789244.stgit@skinsburskii-cloud-desktop.internal.cloudapp.net


Signed-off-by: Wei Liu <wei.liu@kernel.org>