drm/omap: remove OMAP_BO_TILED define

OMAP_BO_TILED does not make sense, as OMAP_BO_TILED_* values are not
bitmasks but normal values. As we already have OMAP_BO_TILED_MASK for
the mask, we can remove OMAP_BO_TILED and use OMAP_BO_TILED_MASK
instead.

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Reviewed-by: Jean-Jacques Hiblot <jjhiblot@ti.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191010120000.1421-6-jjhiblot@ti.com