drm/amdgpu: bypass tiling flag check in virtual display case (v2)

In the Linux kernel, the following vulnerability has been resolved:

drm/amdgpu: bypass tiling flag check in virtual display case (v2)

vkms leverages common amdgpu framebuffer creation, and

also as it does not support FB modifier, there is no need

to check tiling flags when initing framebuffer when virtual

display is enabled.

This can fix below calltrace:

amdgpu 0000:00:08.0: GFX9+ requires FB check based on format modifier

WARNING: CPU: 0 PID: 1023 at drivers/gpu/drm/amd/amdgpu/amdgpu_display.c:1150 amdgpu_display_framebuffer_init+0x8e7/0xb40 [amdgpu]

v2: check adev->enable_virtual_display instead as vkms can be

enabled in bare metal as well.