Currently using pm_runtime with DSS requires the DSS driver to enable
the DSS functional clock before calling pm_runtime_get(). That makes it
impossible to use pm_runtime in DSS as it is meant to be used, with
pm_runtime callbacks.

This patch changes the hwmod database for OMAP4 so that enabling the
hwmod via pm_runtime will also enable the DSS functional clock, allowing
us to use pm_runtime properly in DSS driver.

The DSS HWMOD side is not really correct, not before nor after this
patch, and getting DSS to retention will probably not work currently.
However, it is not supported in the mainline kernel anyway, so this
won't break anything.

So this patch allows us to write the pm_runtime adaptation for the DSS
driver the way it should be done, and the HWMOD/PM side can be fixed
later.
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Signed-off-by: Benoit Cousson <b-cousson@ti.com>
Signed-off-by: Paul Walmsley <paul@pwsan.com>