termios: kill uapi termios.h that are identical to generic one

mandatory-y will have the generic picked for architectures that
don't have uapi/asm/termios.h of their own.  ia64, parisc and
s390 ones are identical to generic, so...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Link: https://lore.kernel.org/r/YxGVXpS2dWoTwoa0@ZenIV


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