Revert "tty: vt: use _IO() to define ioctl numbers"

This reverts commit f1180ca3. Since the
commit, the vt ioctl numbers are defined differently on platforms where
_IOC_NONE is non-zero: alpha, mips, powerpc, sparc.

Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org>
Reported-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Link: https://lore.kernel.org/all/436489B9-E67B-4630-909F-386C30A2AAC9@xenosoft.de/
Link: https://lore.kernel.org/all/97ec2636-915a-498c-903b-d66957420d21@csgroup.eu/
Cc: Nicolas Pitre <nico@fluxnic.net>
Cc: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20250801082613.2564584-1-jirislaby@kernel.org


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>