Changed the default delay of optimizing display data buffer allocations from 0 to 1 second

[0xFireWolf]

Abstract

This is a follow-up for the previous PR (#92) that fixes the garbled screen on Intel Ice Lake platforms.

The community reports that a delay of 1 to 3 seconds is adequate for avoiding the pipe underrun issue on the builtin display without having negative impacts on external displays, and that the default delay of 0 second used in v1.5.4 may lead to both internal and external displays flickering on some laptops.

This PR changes the default delay to 1 second and adds documentation for a hidden device property dbuf-optimizer-delay introduced in the previous PR that allows users to specify a custom delay value.

Updates

This PR also disabled the following submodules on Ice Lake platforms.

• Black screen fix as it is only applicable to SKL/KBL/CFL/CML platforms.
• Force complete modeset as HDMI/DVI connections are not supported by the driver.

Thank you.

-- FireWolf
Oct 8, 2021