drm/armada: Fix compile fail

I reported the include issue for tracepoints a while ago, but nothing
seems to have happened. Now it bit us, since the drm_mm_print
conversion was broken for armada. Fix it, so I can re-enable armada
in the drm-misc build configs.

v2: Rebase just the compile fix on top of Chris' build fix.

Cc: Russell King <rmk+kernel@armlinux.org.uk>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Acked: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1483115932-19584-1-git-send-email-daniel.vetter@ffwll.ch

drivers/gpu/drm/armada/Makefile

@@ -4,3 +4,5 @@ armada-y	+= armada_510.o
 armada-$(CONFIG_DEBUG_FS) += armada_debugfs.o
 
 obj-$(CONFIG_DRM_ARMADA) := armada.o
+
+CFLAGS_armada_trace.o := -I$(src)