[PATCH] synclink.c: replace syncppp with genhdlc

Replace syncppp interface with generic HDLC interface.  Generic HDLC
provides superset of syncppp function.
Signed-off-by: Paul Fulghum <paulkf@microgate.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>