net: qrtr: Cleanup flow control during DEL proc

Flow control cleanup of remote socket is not happening in
case of DEL proc which will cause flow control hit for that
remote socket once the proc is active again.

Cleanup flow control on the reception of DEL proc command.

Change-Id: I9cbaa121d7ca39a887b423ee274652dccaba8a38
Signed-off-by: Arun Prakash <app@codeaurora.org>