trace: rtb: add msm_rtb tracing

Add snapshot of msm_rtb.c and related configuration from
msm-4.19 commit <e56fe938419e> (Merge "uapi: Introduce
V4L2_FLAG_CVPMETADATA_SKIP flag").

Change-Id: Ibce114b5ec3b778a4c89543a7411bb432df79bca
[eberman@codeaurora.org: Add support for removing msm-rtb driver.]
Signed-off-by: Elliot Berman <eberman@codeaurora.org>