msm: camera: isp: Add VFE HW driver support

Add support for VFE HW driver. This HW processes pixels from image
sensor in real time. The VFE HW is controlled by ISP HW Manager.
VFE HW also is responsible for voting for AHB/AXI bandwidth through
the CPAS APIs.

The VFE HW has following blocks -
VFE TOP:
This block creates and manages the MUX resources which are the
input port to the VFE HW.

VFE BUS:
This block creates and manages the BUS Client resources which are
the output port from the VFE HW to DDR.

IRQ Controller Utility:
This block services IRQ from HW and dispatches calls to top half
handlers for subscribed IRQs. It also enqueues the IRQ events to
registered bottom halves.

Tasklet Utitlity:
This is the softirq utility for handling IRQ events in bottom half.

Change-Id: Ic20a5f30c12167b1723967bc2fbe9d95caad76e4
Signed-off-by: Alok Pandey <akumarpa@codeaurora.org>
Signed-off-by: Harsh Shah <harshs@codeaurora.org>
Signed-off-by: Jing Zhou <jzhou70@codeaurora.org>