DRA756: PVR: scanout buffer error

Render node /dev/dri/renderD128 fails

Steps to reproduce:

#start weston using desktop shell
export WAYLAND_DISPLAY=/run/wayland0

# Does not work. By default it tries to use the offscreen render node
# /dev/dri/renderD128.
weston-simple-dmabuf-egl

# Output:
#Warning: zwp_linux_explicit_synchronization_v1 not supported,
#         will not use explicit synchronization
#         PVR:(Error): PVRDisplayBufferCreate: Failed to create display buffer (err=13) [0, ]
#         PVR:(Error): PVRDRIPlaneCreate: Failed to create share/scanout/cursor buffer [0, ]
#         PVR:(Error): PVRDRIBufferCreate: Failed to create plane [0, ]
#         CreateImageShared: Failed to create buffer
#         create_bo failed

# Does work when overriding dri device.
weston-simple-dmabuf-egl -d /dev/dri/card0

Using: meta-ti/recipes-graphics/libgles/ti-sgx-ddk-um_1.17.4948957.bb