usb: dwc2: Remove unnecessary debug prints

Removed unnecessary debug prints about DMA mode for host side
from dwc2_gahbcfg_init() function.

Acked-by: John Youn <johnyoun@synopsys.com>
Signed-off-by: Razmik Karapetyan <razmik@synopsys.com>
Signed-off-by: Grigor Tovmasyan <tovmasya@synopsys.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>