msm: ipa3: fix send_cmd_timeout logic

When sending commands to IPA with timeout, the completion
object needs to be allocated on heap to make sure memory
is still available when EOT is received for this command.

Change-Id: I0228967ca3b33a56489a80833c0565ba2dfe8c2a
CRs-Fixed: 1082708
Acked-by: Ady Abraham <adya@qti.qualcomm.com>
Signed-off-by: Skylar Chang <chiaweic@codeaurora.org>