v4l: Remove vendor specific extension for performance mode

Remove unused control introduced by QCOM for setting performance mode
for the WFD driver. The WFD driver now uses
V4L2_CID_MPEG_VIDC_SET_PERF_LEVEL.

Change-Id: I10c6350209e5910ee3b63b74b51c2ac6a48bb115
Signed-off-by: Deva Ramasubramanian <dramasub@codeaurora.org>