msm: camera: isp: Use only pingpong_bit instead of status

In Dual VFE mode, the 2 VFE can assign different WM to same user stream.
So when updating pingpong address, the pingpong_status can be different
for the 2 VFE. Use just the pingpong_bit along with each VFE WM number
to config ping pong to resolve the split in such a scenario.

Change-Id: I41a1ea8d443d061c5c2ee40d4ea0922456021192
Signed-off-by: Harsh Shah <harshs@codeaurora.org>