media: video: vp_enabled state incorrect after a forced reset

After a forced reset occurred on VP, during a stream_off call,
vp_enabled state was incorrect causing one extra call to
disable_irq. This would result in VP isr to be called whenever
interrupt was triggered.

CRs-Fixed: 418792
Change-Id: Ia66b2d70506d4b06782bc5c25c83587c78f8e9c8
Signed-off-by: Terence Hampson <thampson@codeaurora.org>