Tweak xf86-video-intel for DragonFly 3.7+

* xf86-video-intel 2.21.15+ expects the kernel to set optimal video modes
  on all video outputs

* This is not the case with the current DragonFly implementation. Force
  a reprobe of outputs during X startup

Bug reports:
DragonFlyBSD/DPorts#87
https://bugs.freedesktop.org/show_bug.cgi?id=66494

ports/x11-drivers/xf86-video-intel/diffs/Makefile.diff

@@ -1,6 +1,6 @@
 --- Makefile.orig	2014-01-22 17:00:46.000000000 +0000
 +++ Makefile
-@@ -26,10 +26,23 @@ USE_XORG=	glproto \
+@@ -26,17 +26,32 @@ USE_XORG=	glproto \
  .include <bsd.port.options.mk>
 
  .if defined(WITH_NEW_XORG)
@@ -25,9 +25,11 @@
  MAKE_JOBS_UNSAFE=yes
  PLIST_SUB+=	OLD="@comment "
  EXTRA_PATCHES+=	${PATCHDIR}/extra-src__sna__sna_threads.c \
-@@ -37,6 +50,7 @@ EXTRA_PATCHES+=	${PATCHDIR}/extra-src__s
+ 		${PATCHDIR}/extra-src_sna_kgem.c \
  		${PATCHDIR}/extra-clang \
- 		${PATCHDIR}/extra-i915kms
+-		${PATCHDIR}/extra-i915kms
++		${PATCHDIR}/extra-i915kms \
++		${DFLY_PATCHDIR}/extra-src_sna_sna__display.c
  LIB_DEPENDS+=	libxcb-util.so:${PORTSDIR}/x11/xcb-util
 +.  endif
  .else

ports/x11-drivers/xf86-video-intel/dragonfly/extra-src_sna_sna__display.c

@@ -0,0 +1,11 @@
+--- src/sna/sna_display.c.orig	2013-08-20 20:26:26.000000000 +0000
++++ src/sna/sna_display.c
+@@ -2979,7 +2979,7 @@ static bool sna_probe_initial_configurat
+ 	int width, height;
+ 	int i, j;
+
+-	if (xf86ReturnOptValBool(sna->Options, OPTION_REPROBE, FALSE))
++//	if (xf86ReturnOptValBool(sna->Options, OPTION_REPROBE, FALSE))
+ 		return false;
+
+ 	/* First scan through all outputs and look for user overrides */