spi_mpc8xxx: s/83xx/8xxx/g

spi_mpc8xxx: s/83xx/8xxx/g

Since we renamed the file, we might want to rename the file internals too.

Though we don't bother with changing platform driver name and platform
module alias.  The stuff is legacy and hopefully we'll remove it soon.

Suggested-by: Kumar Gala <[email protected]>
Signed-off-by: Anton Vorontsov <[email protected]>
Cc: David Brownell <[email protected]>
Cc: Benjamin Herrenschmidt <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>