ARM: ixp4xx: fix typos in comments

Various spelling mistakes in comments.
Detected with the help of Coccinelle.

Signed-off-by: Julia Lawall <Julia.Lawall@inria.fr>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20220318103729.157574-26-Julia.Lawall@inria.fr
Link: https://lore.kernel.org/r/20220826112153.438829-1-linus.walleij@linaro.org

'
Signed-off-by: Arnd Bergmann <arnd@arndb.de>