linux-wandboard

OMAPDSS: DPI: use dpi.dsidev to see whether to use dsi pll

Instead of using dpi_use_dsi_pll() to check if dsi pll is to be used, we
can just check if dpi.dsidev != NULL.

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