ARM: dts: Enable sequential load for pil firmware image on sdm845 target

sdm845 target is enabled with sequential load of pil firmware
blobs image, parallel pil loading is not supported.

Change-Id: I38b09641ade72d8e46e4c4a003fc35019b0136b2
Signed-off-by: Sanjay Dwivedi <sanjaykd@codeaurora.org>