alpha: don't reference obsolete termio struct for TC* constants

Similar in nature to ab10727. glibc-2.42
drops the legacy termio struct, but the ioctls.h header still defines some
TC* constants in terms of termio (via sizeof). Hardcode the values instead.

This fixes building Python for example, which falls over like:
  ./Modules/termios.c:1119:16: error: invalid application of 'sizeof' to incomplete type 'struct termio'

Link: https://bugs.gentoo.org/961769
Link: https://bugs.gentoo.org/962600
Signed-off-by: Sam James <sam@gentoo.org>
Reviewed-by: Magnus Lindholm <linmag7@gmail.com>
Link: https://lore.kernel.org/r/6ebd3451908785cad53b50ca6bc46cfe9d6bc03c.1764922497.git.sam@gentoo.org
Signed-off-by: Magnus Lindholm <linmag7@gmail.com>

Author: thesamesam

arch/alpha/include/uapi/asm/ioctls.h

@@ -23,10 +23,10 @@
 #define TCSETSW		_IOW('t', 21, struct termios)
 #define TCSETSF		_IOW('t', 22, struct termios)
 
-#define TCGETA		_IOR('t', 23, struct termio)
-#define TCSETA		_IOW('t', 24, struct termio)
-#define TCSETAW		_IOW('t', 25, struct termio)
-#define TCSETAF		_IOW('t', 28, struct termio)
+#define TCGETA          0x40127417
+#define TCSETA          0x80127418
+#define TCSETAW         0x80127419
+#define TCSETAF         0x8012741c
 
 #define TCSBRK		_IO('t', 29)
 #define TCXONC		_IO('t', 30)