msm: camera: isp: Add missing BUS deinit call

In VFE core init, there is a call to BUS init. But the deinit
call to BUS was missing. This would result in memory leak in IRQ
controller and possible bugs by stale data in variables. Added
the missing call.

Change-Id: I8b909c56c5d72afcd96a03e560cd3f27963a7249
Signed-off-by: Harsh Shah <harshs@codeaurora.org>