usb: dwc3: core: add support for realtek SoCs custom's global register start address

usb: dwc3: core: add support for realtek SoCs custom's global register start address

The Realtek RTD SoCs were designed with the global register address
offset at 0x8100. The default address offset is constant at
DWC3_GLOBALS_REGS_START (0xc100). Therefore, add a check if the
compatible name of the parent is realtek,rtd-dwc3, then global
register start address will remap to 0x8100.

Signed-off-by: Stanley Chang <stanley_chang@realtek.com>
Acked-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com>
Link: https://lore.kernel.org/r/20230505025104.18321-1-stanley_chang@realtek.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>