qcom: qpnp-haptics: extend stop timer for a longer request

Haptics works as a timed output device and it doesn't expect another
enable request while current one is still in progress. If a new
enabling request comes in and its duration is longer than current
pattern's expiry then extend the stop timer.

CRs-Fixed: 2171601
Change-Id: I1f1f4e9a58140114a41d2af54b06cd798332eae4
Signed-off-by: Fenglin Wu <fenglinw@codeaurora.org>