vidc: Use O_SYNC for pmem device.

Necessary as usageflags are indicates an uncached device. Without O_SYNC
buffers become corrupt leading to HW_ERRORS in vidc.

This commit will hopefully fix the video playback issue.
Merge pull request #9 from Flyhalf205/cm-10.1

vidc: Use O_SYNC for pmem device.
Merge commit '74f5eb7' into vanilla
Fix LED notifications

Credit to Flyhalf205 for pointing out the fix