Fix the build when DRI is enabled

configure.ac

@@ -392,7 +392,8 @@ AM_CONDITIONAL(DRI, test x$DRI = xyes)
 if test "$DRI" = yes; then
 	AC_DEFINE(XORGDRI,1,[Build DRI extension])
 	AC_DEFINE(_XORGDRI_SERVER_,1,[XORGDRI internal define])
-	REQUIRED_MODULES="$REQUIRED_MODULES xf86driproto"
+	PKG_CHECK_MODULES([DRIPROTO], [xf86driproto])
+	AC_SUBST(DRIPROTO_CFLAGS)
 fi
 AC_DEFINE(XINPUT,1,[Support X Input extension])
 EXTENSION_LIBS="$EXTENSION_LIBS "'$(top_builddir)/Xi/libXi.la'

hw/xfree86/dri/Makefile.am

@@ -1,5 +1,5 @@
 libdri_la_LTLIBRARIES = libdri.la
-libdri_la_CFLAGS = -I$(top_srcdir)/hw/xfree86/common -I$(top_srcdir)/hw/xfree86/os-support/bus -I$(top_srcdir)/GL/glx/ -I$(top_srcdir)/GL/include -DXF86DRI -DXORG_VERSION_CURRENT=\"100\"
+libdri_la_CFLAGS = -I$(top_srcdir)/hw/xfree86/common -I$(top_srcdir)/hw/xfree86/os-support/bus -I$(top_srcdir)/GL/glx/ -I$(top_srcdir)/GL/include -DXF86DRI -DXORG_VERSION_CURRENT=\"100\" @DRIPROTO_CFLAGS@
 libdri_la_LDFLAGS = -module -avoid-version
 libdri_ladir = @moduledir@/extensions
 libdri_la_SOURCES = \

hw/xfree86/os-support/linux/drm/Makefile.am

@@ -1,4 +1,8 @@
-INCLUDES = -I$(srcdir)/../../shared/drm/kernel
+INCLUDES = -I$(srcdir)/../../shared/drm/kernel \
+           -I$(srcdir)/../.. \
+           -I$(srcdir)/../../bus \
+           -I$(srcdir)/../../../dri \
+           -I$(srcdir)/../../../common
 
 sdklibdir = $(libdir)/xorg
 sdklib_LIBRARIES = libxorglinuxdrm.a