msm: vidc: Change enum values of V4L2_MPEG_VIDEO_H264_LOOP_FILTER_MODE_*

Having ENABLED = 0 and DISABLED = 1 is somewhat misleading and
introduces bugs.  Flip them around so it's more intuitive.

Also the deblocker is disabled by default in hardware, change the driver
default to reflect that.

Change-Id: I689ffd431d8c6118cff51cf9be58df6cf83ba436
Signed-off-by: Deva Ramasubramanian <dramasub@codeaurora.org>