dmaengine: mv_xor_v2: Fix an error code.

If the probe is deferred, -EPROBE_DEFER should be returned, not
+EPROBE_DEFER.

Fixes: 3cd2c313 ("dmaengine: mv_xor_v2: Fix clock resource by adding a register clock")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Link: https://lore.kernel.org/r/201170dff832a3c496d125772e10070cd834ebf2.1679814350.git.christophe.jaillet@wanadoo.fr


Signed-off-by: Vinod Koul <vkoul@kernel.org>