dmaengine: ste_dma40: fix typo in comment

Spelling mistake (triple letters) in comment.
Detected with the help of Coccinelle.

Signed-off-by: Julia Lawall <Julia.Lawall@inria.fr>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20220521111145.81697-17-Julia.Lawall@inria.fr


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