microblaze: fix typos in comments

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

Signed-off-by: Julia Lawall <Julia.Lawall@inria.fr>
Link: https://lore.kernel.org/r/20220430191122.8667-1-Julia.Lawall@inria.fr


Signed-off-by: Michal Simek <michal.simek@amd.com>