ppp: Move ioctl definitions from if_ppp.h to new ppp-ioctl.h

This moves the definitions of the ioctls, constants and structures
relating to the ppp_generic interface to userspace out from if_ppp.h
to a new file, ppp-ioctl.h.  The new file has my copyright since I
designed and implemented the ppp_generic interface in the late 1990s.
None of the contents of this file comes from the original if_ppp.h
published by Carnegie Mellon University.

Of the remainder of if_ppp.h, only the PPP_MTU definition was being
used, and this replaces the uses of it with PPP_MRU (which is identical).
Therefore, this replaces the entire file with the single line

#include <linux/ppp-ioctl.h>

which clearly doesn't contain any CMU code.  Thus I have removed the
CMU copyright notice with its problematic advertising clause, and in
fact since it's only one trivial line I have not added any other
copyright notice.

Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/Documentation/networking/ppp_generic.txt b/Documentation/networking/ppp_generic.txt
index 15b5172..091d202 100644
--- a/Documentation/networking/ppp_generic.txt
+++ b/Documentation/networking/ppp_generic.txt
@@ -342,7 +342,7 @@
 				numbers on received multilink fragments
 	SC_MP_XSHORTSEQ		transmit short multilink sequence nos.
 
-  The values of these flags are defined in <linux/if_ppp.h>.  Note
+  The values of these flags are defined in <linux/ppp-ioctl.h>.  Note
   that the values of the SC_MULTILINK, SC_MP_SHORTSEQ and
   SC_MP_XSHORTSEQ bits are ignored if the CONFIG_PPP_MULTILINK option
   is not selected.
@@ -358,7 +358,7 @@
 
 * PPPIOCSCOMPRESS sets the parameters for packet compression or
   decompression.  The argument should point to a ppp_option_data
-  structure (defined in <linux/if_ppp.h>), which contains a
+  structure (defined in <linux/ppp-ioctl.h>), which contains a
   pointer/length pair which should describe a block of memory
   containing a CCP option specifying a compression method and its
   parameters.  The ppp_option_data struct also contains a `transmit'
@@ -395,7 +395,7 @@
 
 * PPPIOCSNPMODE sets the network-protocol mode for a given network
   protocol.  The argument should point to an npioctl struct (defined
-  in <linux/if_ppp.h>).  The `protocol' field gives the PPP protocol
+  in <linux/ppp-ioctl.h>).  The `protocol' field gives the PPP protocol
   number for the protocol to be affected, and the `mode' field
   specifies what to do with packets for that protocol: