msm: cam: reqmgr: Add request manager driver

Add camera request manager which communicates with different
camera hardware drivers for synchronization of applying
particular settings. These settings will be applied for
every frame. Below are the changes included:
- Create and destroy of session and link
- Utilities functions for camera request manager
- Interface to userspace component
- Setup workqueue for handling tasks such as schedule and process request

CRs-Fixed: 1108532
Change-Id: Ibb436b7aa161ebbedff808da2ac86221720f9af1
Signed-off-by: Sagar Gore <sgore@codeaurora.org>
Signed-off-by: Suresh Vankadara <svankada@codeaurora.org>