msm: ADSPRPC: Free interrupted contexts on device close

The interrupted context list keeps track of all requests made
to the remote processor for which a response has not been
received and were interrupted by APPS processor. Free saved
contexts from interrupt list on device close to avoid memory leaks.

Change-Id: I5e4515b8d06d981a066a812a57242662b5bb82b9
Acked-by: Sathish Ambley <sambley@qti.qualcomm.com>
Signed-off-by: Mitchel Humpherys <mitchelh@codeaurora.org>