drivers: bus: ocp2scp: add pdata support

ocp2scp was not having pdata support which makes *musb* fail for non-dt
boot in OMAP platform. The pdata will have information about the devices
that is connected to ocp2scp. ocp2scp driver will now make use of this
information to create the devices that is attached to ocp2scp.

This is needed to fix MUSB regression caused by commit c9e4412a
(arm: omap: phy: remove unused functions from omap-phy-internal.c)

Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
Acked-by: Felipe Balbi <balbi@ti.com>
[tony@atomide.com: updated comments for regression info]
Signed-off-by: Tony Lindgren <tony@atomide.com>