OMAPDSS: DPI: Remove cpu_is_xxxx checks

The OMAP3 checks have been removed and replaced by a dss feature
FEAT_DPI_USES_VDDS_DSI for cleaner implementation. The patches
"OMAP: DSS2: enable VDDS_DSI when using DPI" (8a2cfea8cc) by Tomi Valkeinen
<tomi.valkeinen@nokia.com> and "ARM: omap: fix oops in
drivers/video/omap2/dss/dpi.c" (4041071571) by Russell King
<rmk+kernel@arm.linux.org.uk> had introduced these checks. As it is evident
from these patches a dependency exists for some DSS pins on VDDS_DSI which is
better shown by dss feature FEAT_DPI_USES_VDDS_DSI.

Signed-off-by: Chandrabhanu Mahapatra <cmahapatra@ti.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
diff --git a/drivers/video/omap2/dss/dss_features.h b/drivers/video/omap2/dss/dss_features.h
index 996ffcb..26d43a4 100644
--- a/drivers/video/omap2/dss/dss_features.h
+++ b/drivers/video/omap2/dss/dss_features.h
@@ -50,6 +50,7 @@
 	FEAT_DSI_VC_OCP_WIDTH,
 	FEAT_DSI_REVERSE_TXCLKESC,
 	FEAT_DSI_GNQ,
+	FEAT_DPI_USES_VDDS_DSI,
 	FEAT_HDMI_CTS_SWMODE,
 	FEAT_HDMI_AUDIO_USE_MCLK,
 	FEAT_HANDLE_UV_SEPARATE,