console: Fill in struct consw argument names

Reading the function declarations for the console callbacks lacks any
hints as to what the arguments are. Instead of going and digging around in
various implementations that may each only have a subset of the callbacks,
name all the arguments in the declaration. This has no functional change.

Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>