tty: vt: use sane types for userspace API

tty: vt: use sane types for userspace API

As discussed earlier (see the Link below), use the preferred ioctl types
in vt.h (__u8, __u16, ...).

These types are already used for the new VT_GETCONSIZECSRPOS.
Therefore, the necessary includes are already present. Since now, the
types are used for every structure defined in the header now.

Note the kernel is built with -funsigned-char, therefore 'char' becomes
'__u8' in here.

Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org>
Cc: Nicolas Pitre <nico@fluxnic.net>
Link: https://lore.kernel.org/all/p7p83sq1-4ro2-o924-s9o2-30spr74n076o@syhkavp.arg/
Reviewed-by: Nicolas Pitre <npitre@baylibre.com>
Link: https://lore.kernel.org/r/20250611100319.186924-7-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>