weston-init: use the drm/kms backend rather than fbdev one for qemux86 machines
The fbdev backend is not documented, and not the default;
as the emulated hardware in qemu now supports DRM/KMS
(both std and virtio), we should align with upstream default
and vast majority of users. Empty init file will cause
weston to default to the KMS backend.
Note that 3D acceleration via virgl is not required; the backend
renders fine via the software driver in mesa. However, kvm
is more or less required to keep the UI responsive.
Also, other qemu targets (mips and arm in particular) continue
to use the fbdev backend, as in the absence of kvm, the performance
of software GL paths falls to unacceptable level.
Signed-off-by: Alexander Kanavin <alex.kanavin@gmail.com> Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
