omapdss: dss: Fix clocks on OMAP363x

Commit 185bae10 ("OMAPDSS: DSS: Cleanup
cpu_is_xxxx checks") broke the DSS clocks configuration by erroneously
using the clock parameters applicable to all other OMAP34xx SoCs for the
OMAP363x. This went unnoticed probably because the cpu_is_omap34xx()
class check wasn't seen as matching the OMAP363x subclass.

Fix it by checking for the OMAP363x subclass before checking for the
OMAP34xx class.

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