msm: vidc: Correct extradata naming inconsistencies

Drop the "INDEX" in the names of some of the extradatas.  In preparation
introduce new enums without "INDEX" in the name so all clients can
migrate.

Change-Id: I4bfe35d28054fd365b9bd08925485f5478439d4a
Signed-off-by: Deva Ramasubramanian <dramasub@codeaurora.org>