Merge branch 'fixes-for-v4.9-rc5' of http://git.agner.ch/git/linux-drm-fsl-dcu into drm-fixes

Yet another small batch of fixes. Two of the patches I had prepared
since quite some time, but they did not seem to affect operation in
a visible manner so far. Until recently, when I discovered the third
issue (disable planes before disabling CRTC), which made the two
previous fixes necessary.

* 'fixes-for-v4.9-rc5' of http://git.agner.ch/git/linux-drm-fsl-dcu:
  drm/fsl-dcu: disable planes before disabling CRTC
  drm/fsl-dcu: update all registers on flush
  drm/fsl-dcu: do not update when modifying irq registers