Remove Solaris module code (#515)

This code has not been updated for a long time, and nominally targets
an OS whose owner (Oracle) has all but abandoned.  It includes
zlib code which has CVEs against it, and it is unknown whether any
of them would be exploitable in this context.

Illumos, which is an OpenSolaris fork, has forked Solaris-native
drivers, which should probably work with the user-space pppd code
here.

Signed-off-by: Paul Mackerras <[email protected]>

Makefile.am

@@ -6,21 +6,7 @@ if PPP_WITH_PLUGINS
 SUBDIRS += pppd/plugins
 endif
 
-DIST_SUBDIRS = $(SUBDIRS) common include modules scripts
-
-#
-# *HACK*
-#   This is to work around the kernel module for PPP on Sun Solaris
-if SUNOS
-all-am:
-	(cd solaris ; $(MAKE) -f Makefile)
-
-clean-generic:
-	(cd solaris ; $(MAKE) -f Makefile clean)
-
-install-am:
-	(cd solaris ; $(MAKE) -f Makefile install)
-endif
+DIST_SUBDIRS = $(SUBDIRS) include scripts
 
 install-data-hook:
 	(cd $(DESTDIR)/$(sysconfdir)/$(PACKAGE) ; \
@@ -54,27 +40,6 @@ EXTRA_README = \
     SETUP \
     Submitting-patches.md
 
-EXTRA_SOLARIS = \
-    solaris/Makedefs \
-    solaris/Makedefs.gcc \
-    solaris/Makedefs.sol2 \
-    solaris/Makefile.sol2 \
-    solaris/Makefile.sol2-64 \
-    solaris/Makefile.sol2-64x \
-    solaris/Makefile.sol2gcc \
-    solaris/Makefile.sol2gcc-64 \
-    solaris/Makefile.sol2gcc-64x \
-    solaris/Makefile.top \
-    solaris/ppp_ahdlc.c \
-    solaris/ppp_ahdlc_mod.c \
-    solaris/ppp.c \
-    solaris/ppp_comp.c \
-    solaris/ppp_comp_mod.c \
-    solaris/ppp.conf \
-    solaris/ppp_mod.c \
-    solaris/ppp_mod.h
-
 EXTRA_DIST= \
     $(sample_DATA) \
-    $(EXTRA_README) \
-    $(EXTRA_SOLARIS)
+    $(EXTRA_README)