drm/msm/sde: remove legacy 8996 catalog support

The 8996 hardware catalog is outdated and legacy support.
It is not required after 8996 target moved to dtsi
based parsing. Any future sde chip can add the
catalog structures if it does not want support the
DTSI parsing.

Change-Id: Id0ab6c100f6d71e8970623595c7a1cf4332e2304
Signed-off-by: Dhaval Patel <pdhaval@codeaurora.org>