unix: add Termio, Winsize, Statfs_t, TC[GS]ET, Mkdir and Mknod for AIX

These changes add Termio/Winsize/Statfs_t for AIX, constants TC[GS]ET and the syscalls Mkdir and Mknod.
It also changes the comments for AIX which still were talking about Linux and glibc.

Change-Id: I64325330328d6e16cff540f103fdfa533b7d8f5b
Reviewed-on: https://go-review.googlesource.com/136295
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Tobias Klauser <tobias.klauser@gmail.com>

unix/zerrors_aix_ppc.go

@@ -867,6 +867,9 @@ const (
 	TAB2                          = 0x800
 	TAB3                          = 0xc00
 	TABDLY                        = 0xc00
+	TCFLSH                        = 0x540c
+	TCGETA                        = 0x5405
+	TCGETS                        = 0x5401
 	TCIFLUSH                      = 0x0
 	TCIOFF                        = 0x2
 	TCIOFLUSH                     = 0x2
@@ -915,6 +918,15 @@ const (
 	TCP_TIMESTAMP_OPTLEN          = 0xc
 	TCP_UNSETPRIV                 = 0x28
 	TCSAFLUSH                     = 0x2
+	TCSBRK                        = 0x5409
+	TCSETA                        = 0x5406
+	TCSETAF                       = 0x5408
+	TCSETAW                       = 0x5407
+	TCSETS                        = 0x5402
+	TCSETSF                       = 0x5404
+	TCSETSW                       = 0x5403
+	TCXONC                        = 0x540b
+	TIOC                          = 0x5400
 	TIOCCBRK                      = 0x2000747a
 	TIOCCDTR                      = 0x20007478
 	TIOCCONS                      = 0x80047462