drm/msm/sde: update true inline rotation maxdownscale limit

Update the true inline rotation real-time maxdownscale
limit as per hardware programming recommendation.
Update relevant checks and expose the same through
pipe capabilities to user-mode. Retain the older
rt maxdownscale capability to keep backward compatibility,
until user-mode switches to the new parameters.

Change-Id: I15b903a1c7b2d77d6cd355e8433ddd0b253a2935
Signed-off-by: Veera Sundaram Sankaran <veeras@codeaurora.org>