Add HDMI output for linux-yocto

[m5p3nc3r]

Configuration is only added if building for X11 or Waylamd targets

Open questions for this pull request:

1, CMA memory is extended from 256M to 896M

• amlogic-image-sato boots fine without this patch, but I'm assuming its added for multiple displays, video decode etc?
• I have hijacked the patch from linux-meson64-5.4, not sure if this is ok?

2, I am assuming that CMA is only used by the video subsystem,

• If this is true, adding CONFIG_CMA only when HDMI output is required should be ok
• If not, I will move CMA_CONFIG into the base/generic meson configuration

[superna9999]

Hi,

896M is only needed to decoded 4k-10bit VP9 videos, otherwise 256MiB is enough for 4k DRM display only.

I think you can remove the 896M CMA patch unless you enable the video decoder

[m5p3nc3r]

That's what I assumed the patch was for. Thanks for the clarification. I have removed the CMA patch now, so should be ready for merge if you are happy.