linux-user: Add generic 'termbits.h' for some archs

linux-user: Add generic 'termbits.h' for some archs

This patch introduces a generic 'termbits.h' file for following
archs: 'aarch64', 'arm', 'i386, 'm68k', 'microblaze', 'nios2',
'openrisc', 'riscv', 's390x', 'x86_64'.

Since all of these archs have the same termios flag values and
same ioctl_tty numbers, there is no need for a separate 'termbits.h'
file for each one of them. For that reason one generic 'termbits.h'
file was added for all of them and an '#include' directive was
added for this generic file in every arch 'termbits.h' file.

Also, some of the flag values that were missing were added in this
generic file so that it matches the generic 'termibts.h' and 'ioctls.h'
files from the kernel: 'asm-generic/termbits.h' and 'asm-generic/ioctls.h'.

Signed-off-by: Filip Bozuta <Filip.Bozuta@syrmia.com>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20200723210233.349690-2-Filip.Bozuta@syrmia.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>