Use DMA engine for fullscreen updates and bypass mode for partial
updates. This gives major boost on rk27generic:
default ARM:AHB:APB 200💯50
HEAD 1/1: 26.3fps 1/4: 105.0fps
patched 1/1: 116.5fps 1/4: 249.5fps
with freq scalling NORMAL mode ARM:AHB:APB 50:50:50
HEAD 1/1: 13.1fps 1/4: 52.5fps
patched 1/1: 54.5fps 1/4: 119.0fps
Tested on rk27generic noname DAP and on Hifimans.
Change-Id: Id9dd4d2d61542c7ea6b5c6336b170d6357cefde9
