drm: omapdrm: hdmi: Don't allocate PHY features dynamically

There's no need to allocate memory dynamically to duplicate the contents
of a const structure, only to store the memory pointer in a const
pointer field. Just use the original structures directly.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>