Enabled CRTSwitchres support for KMS DRM video

[kozakt]

Description

Switchres now supports DRM KMS linux video driver, this change will enable support for it in RetroArch builds.

[substring]

Hi,

This is not necessary, KMS/DRM modeswitching works perfectly without this PR, adding this file could be dangerous. In KMS/DRM, Switchres is used as a modeline generator and doesn't need to handle anything else since Retroarch is bare metal enough to do the modeswitching itself once it has the modeline -> see #15131 KMS modeswitching works since March 2023

The file you're adding requires a patched kernel that with user modes added through an IOCTL, which is the case absolutely no main distro, just a few niche ones (or people compiling their own kernel).

[kozakt]

Well, I'm testing with Raspberry Pi 5 and command line only Raspberry Pi LIte and mode switching doesn't work without this change. Also, I'm not patching kernel or anything, just stock Raspberry Pi LIte OS.
With this change, mode switching actually starting to work properly.

[substring]

Better investigate why it doesn't work without this. Ping me on discord. I tested the KMS modeswitching on Pi4 as well as PC when I wrote it.

[LibretroAdmin]

Seems to be a build error for CI Linux (i686)