AMLCodec: fix contrast setting

[samnazarko]

Description'

This fixes contrast setting to match what the kernel expects.

Motivation and Context

This can be fixed in the kernel; but changes are unlikely to be made here for a variety of platforms; so this quick fix is probably better.

How Has This Been Tested?

Tested on AMLogic 3.10 and 3.14

Screenshots (if appropriate):

Types of change

• Bug fix (non-breaking change which fixes an issue)
• Clean up (non-breaking change which removes non-working, unmaintained functionality)
• Improvement (non-breaking change which improves existing functionality)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that will cause existing functionality to change)
• Cosmetic change (non-breaking change that doesn't touch code)
• None of the above (please explain below)

Checklist:

• My code follows the Code Guidelines of this project
• My change requires a change to the documentation, either Doxygen or wiki
• I have updated the documentation accordingly
• I have read the Contributing document
• I have added tests to cover my change
• All new and existing tests passed

[lrusak]

@samnazarko is there a reason this was set to 255? is there a chance that some amlogic kernel use that value?

[samnazarko]

This comes with 3.0.x kernels (early MX6 days).
As Kodi + amcodec only supports >=3.10; this is the correct way to handle this.

[MartijnKaijser]

jenkins build this please

[MartijnKaijser]

jenkins build this please