[media] msi001: cleanups / renames

Rename state from s to dev. Rename some other things. Fix indentations.
Disable driver unbind via sysfs.

indentation prevent unload

Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>