Tweak SOF timestamp recovery logic to handle sending timestamp for
first frame. This is needed when due priority inversion, ISP context
notifies timestamp before SOF.
CRs-Fixed: 3085335
Change-Id: I9baea8d906bb8f820c7aeb2d7d4ae1c1c6f348b2
Signed-off-by: Anand Ravi <quic_ananravi@quicinc.com>