st/xorg: Fixup configure

Make sure we always test for XEXT version.
Make sure that the user has a recent version of libkms and libdrm installed.

Note that the st/xorg code requires so new versions to work but these are
needed to make a proper vmwgfx_drv.so driver which is the only real user.

Cherry picked from 46cf606cd3
Conflicts:

	configure.ac

configure.ac

@@ -22,6 +22,8 @@ LIBDRM_REQUIRED=2.4.15
 LIBDRM_RADEON_REQUIRED=2.4.17
 DRI2PROTO_REQUIRED=2.1
 GLPROTO_REQUIRED=1.4.11
+LIBDRM_XORG_REQUIRED=2.4.17
+LIBKMS_XORG_REQUIRED=1.0.0
 
 dnl Check for progs
 AC_PROG_CPP
@@ -1203,7 +1205,7 @@ yes)
             GALLIUM_STATE_TRACKERS_DIRS="$GALLIUM_STATE_TRACKERS_DIRS egl"
         fi
         # Have only tested st/xorg on 1.6.0 servers
-        PKG_CHECK_MODULES(XORG, [xorg-server >= 1.6.0],
+        PKG_CHECK_MODULES(XORG, [xorg-server >= 1.6.0 libdrm >= $LIBDRM_XORG_REQUIRED libkms >= $LIBKMS_XORG_REQUIRED],
             HAVE_XORG="yes"; GALLIUM_STATE_TRACKERS_DIRS="$GALLIUM_STATE_TRACKERS_DIRS xorg",
             HAVE_XORG="no")
         ;;
@@ -1223,9 +1225,9 @@ yes)
             fi
             ;;
         xorg)
-	    PKG_CHECK_MODULES(XEXT, [xextproto >= 7.0.99.1],
-                  HAVE_XEXTPROTO_71="yes"; DEFINES="$DEFINES -DHAVE_XEXTPROTO_71",
-                  HAVE_XEXTPROTO_71="no")
+            PKG_CHECK_MODULES([LIBDRM_XORG], [libdrm >= $LIBDRM_XORG_REQUIRED])
+            PKG_CHECK_MODULES([LIBKMS_XORG], [libkms >= $LIBKMS_XORG_REQUIRED])
+            HAVE_XORG="yes"
             ;;
         es)
             # mesa/es is required to build es state tracker
@@ -1237,6 +1239,12 @@ yes)
     ;;
 esac
 
+if test "x$HAVE_XORG" = xyes; then
+    PKG_CHECK_MODULES(XEXT, [xextproto >= 7.0.99.1],
+        HAVE_XEXTPROTO_71="yes"; DEFINES="$DEFINES -DHAVE_XEXTPROTO_71",
+        HAVE_XEXTPROTO_71="no")
+fi
+
 AC_ARG_WITH([egl-displays],
     [AS_HELP_STRING([--with-egl-displays@<:@=DIRS...@:>@],
         [comma delimited native displays libEGL supports, e.g.