OMAP: DSS2: Add Kconfig option for DPI display type

This allows us to disable DPI on systems that do not have it

Signed-off-by: Roger Quadros <roger.quadros@nokia.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@nokia.com>
diff --git a/drivers/video/omap2/dss/Makefile b/drivers/video/omap2/dss/Makefile
index 980c72c..d71b5d9 100644
--- a/drivers/video/omap2/dss/Makefile
+++ b/drivers/video/omap2/dss/Makefile
@@ -1,5 +1,6 @@
 obj-$(CONFIG_OMAP2_DSS) += omapdss.o
-omapdss-y := core.o dss.o dispc.o dpi.o display.o manager.o overlay.o
+omapdss-y := core.o dss.o dispc.o display.o manager.o overlay.o
+omapdss-$(CONFIG_OMAP2_DSS_DPI) += dpi.o
 omapdss-$(CONFIG_OMAP2_DSS_RFBI) += rfbi.o
 omapdss-$(CONFIG_OMAP2_DSS_VENC) += venc.o
 omapdss-$(CONFIG_OMAP2_DSS_SDI) += sdi.o