drm: Clear fd/handle callbacks in struct drm_driver

Clear all assignments of struct drm_driver's fd/handle callbacks to
drm_gem_prime_fd_to_handle() and drm_gem_prime_handle_to_fd(). These
functions are called by default. Add a TODO item to convert vmwgfx
to the defaults as well.

v2:
	* remove TODO item (Zack)
	* also update amdgpu's amdgpu_partition_driver

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Simon Ser <contact@emersion.fr>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Acked-by: Jeffrey Hugo <quic_jhugo@quicinc.com> # qaic
Link: https://patchwork.freedesktop.org/patch/msgid/20230620080252.16368-3-tzimmermann@suse.de