Downscale blur HW block support is added from MDSS 9.x. The block
can be used to downscale the layer mixer output before feeding it to
the writeback block. It can be used for both writeback & concurrent
writeback usecases. Add hw files and the respective blocks in sw to
program the downscale blur block.
Change-Id: Ic5787e1655eff5ef0960b7569e48d2f35d23bfc9
Signed-off-by: Veera Sundaram Sankaran <veeras@codeaurora.org>