vc4: Switch to using the libdrm-provided vc4_drm.h.

The required version is set to .69 for the getparam ioctl that will be
used in the next commit.
diff --git a/configure.ac b/configure.ac
index 6ea1f2c..3799d8d 100644
--- a/configure.ac
+++ b/configure.ac
@@ -75,6 +75,7 @@
 LIBDRM_NVVIEUX_REQUIRED=2.4.66
 LIBDRM_NOUVEAU_REQUIRED=2.4.66
 LIBDRM_FREEDRENO_REQUIRED=2.4.67
+LIBDRM_VC4_REQUIRED=2.4.69
 DRI2PROTO_REQUIRED=2.6
 DRI3PROTO_REQUIRED=1.0
 PRESENTPROTO_REQUIRED=1.0
@@ -2467,6 +2468,7 @@
             ;;
         xvc4)
             HAVE_GALLIUM_VC4=yes
+            PKG_CHECK_MODULES([VC4], [libdrm_vc4 >= $LIBDRM_VC4_REQUIRED])
             gallium_require_drm "vc4"
             gallium_require_drm_loader