drm/omap: remove -Werror from Makefile

Having -Werror in the omapdrm Makefile makes development and debugging a
PITA. Let's remove it.
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>

drivers/gpu/drm/omapdrm/Makefile

@@ -6,7 +6,7 @@
 obj-y += dss/
 obj-y += displays/
 
-ccflags-y := -Iinclude/drm -Werror
+ccflags-y := -Iinclude/drm
 omapdrm-y := omap_drv.o \
 	omap_irq.o \
 	omap_debugfs.o \