OMAPDSS: features: remove unused DSI PLL features

Now that the DSS has the common DSS PLL, we no longer use the DSI PLL
feature flags from dss_features.c.

Remove all the unused feature flags.

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>

diff --cc drivers/video/fbdev/omap2/dss/dss_features.c
Simple merge

diff --cc drivers/video/fbdev/omap2/dss/dss_features.h
Simple merge