msm: camera: Dynamically find the request to be deleted

This change updates logic to dynamically determine which
request needs to be deleted from the hashmap based on
which request was last applied and taking into consideration
the pd delay of the device as well.

Change-Id: Ic6e3d69a63f1b16b009813f5e65dc7894daf20d7
Signed-off-by: vhajeri <vhajeri@codeaurora.org>
Signed-off-by: Karthik Anantha Ram <kartanan@codeaurora.org>
Signed-off-by: Jigarkumar Zala <jzala@codeaurora.org>
Signed-off-by: Venkat Chinta <vchinta@codeaurora.org>