MLK-22045-3 cdns3: Add cdns3_generic_peripheral DM gadget driver
Add cdns3_generic_peripheral DM gadget driver for i.MX8QM and QXP.
The driver flag is set to CONFIG_DM_USB_GADGET and
CONFIG_SPL_DM_USB_GADGET while using SPL, and the driver is belong to
UCLASS_USB_GADGET_GENERIC uclass.
For the DM gadget driver, it will parse the reg, clocks and usbphy
properties from node in DTS. So the power and clks of cdns3 controller
and cdns3 phy will be both enabled in DM gadget driver.
Signed-off-by: Sherry Sun <sherry.sun@nxp.com>