change termios structures to match glibc headers

removed termios2, termio, winsize. these seem to be kernel-level structures.
also, the termios expected by cfsetospeed, et al should have c_ispeed and
 c_ospeed.

src/core/sys/posix/termios.d

@@ -138,16 +138,6 @@ version( linux )
     enum NCCS   = 32;
 
     struct termios
-    {
-        tcflag_t   c_iflag;
-        tcflag_t   c_oflag;
-        tcflag_t   c_cflag;
-        tcflag_t   c_lflag;
-        cc_t       c_line;
-        cc_t[NCCS] c_cc;
-    }
-
-    struct termios2
     {
         tcflag_t   c_iflag;
         tcflag_t   c_oflag;
@@ -159,26 +149,6 @@ version( linux )
         speed_t    c_ospeed;
     }
 
-    struct winsize
-    {
-        ushort ws_row;
-        ushort ws_col;
-        ushort ws_xpixel;
-        ushort ws_ypixel;
-    }
-
-    enum NCC = 8;
-
-    struct termio
-    {
-        ushort c_iflag;
-        ushort c_oflag;
-        ushort c_cflag;
-        ushort c_lflag;
-        ubyte c_line;
-        ubyte[NCC] c_cc;
-    }
-
     enum VEOF       = 4;
     enum VEOL       = 11;
     enum VERASE     = 2;