drm/nouveau/device: fix changing endianess code to work on older GPUs

drm/nouveau/device: fix changing endianess code to work on older GPUs

commit dcd292c172493067a72672b245a3dd1bcf7268dd upstream.

With this we try to detect if the endianess switch works and assume LE if
not. Suggested by Ben.

Fixes: 51c05340e407 ("drm/nouveau/device: detect if changing endianness failed")
Signed-off-by: Karol Herbst <kherbst@redhat.com>
Cc: <stable@vger.kernel.org> # v5.8+
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>