usb: musb: dsps: control module handling (quirk)

am335x uses nop transceiver driver and need to enable builtin phy
by writing into usb_ctrl register available in system control
module register space. This is being added at musb glue driver
layer until a separate system control module driver is available.

Proper solution is to make use of control module driver, but it is
not expected to be ready soon.

Other options available are providing control module register space
as memory resource via DT or using omap hwmod.

DT approach has been rejected by Rob Herring, while resources are
being moved from hwmod to DT. And both of the above approaches
require that control module registers be configured in wrapper
itself requring a quirk in driver as well as DT or hwmod.

Here another option is used, providing driver with control module
register physical address. Even though this a hack, there is no other
option left till control module driver is ready. As of now only
am335x is using dsps wrapper, and so driver is made aware of am335x
control module physical address.

Please note that this is a temporary arrangment till omap control
module driver is available.

[afzal@ti.com: limit quirk to dsps wrapper]

Signed-off-by: Santhapuri, Damodar <damodar.santhapuri@ti.com>
Signed-off-by: Ajay Kumar Gupta <ajay.gupta@ti.com>
Signed-off-by: Ravi Babu <ravibabu@ti.com>
Signed-off-by: Afzal Mohammed <afzal@ti.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>