drm/msm/sde: update scaler property definition and type

Blob properties under DRM require a new blob to be created for
each unique set of incoming data. By changing the scaler property
to accept an incoming user space pointer and using copy_from_user
to explicitly copy out the structure data each time the property
is set, the user space client avoids the need to create new
DRM blob objects when the scaler config needs to be updated.

Change-Id: I07d4d095b69ddd38e2bf03de61ad51714df84adb
Signed-off-by: Clarence Ip <cip@codeaurora.org>