Drivers: hv: vmbus: Remove the unused HV_LOCALIZED channel affinity logic

The logic is unused since commit 509879bd

 ("Drivers: hv: Introduce
a policy for controlling channel affinity").

This logic assumes that a channel target_cpu doesn't change during the
lifetime of a channel, but this assumption is incompatible with the new
functionality that allows changing the vCPU a channel will interrupt.

Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com>
Link: https://lore.kernel.org/r/20200406001514.19876-9-parri.andrea@gmail.com
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>