USB: dwc2: Add OTG support for Ingenic SoCs.

Add OTG support for the JZ4775 SoC, the JZ4780 SoC, the X1000 SoC,
the X1600 SoC, the X1700 SoC, the X1830 SoC, and the X2000 SoC
from Ingenic.

Introduce support for disable Ingenic overcurrent detection, once
selected, it enables the GOTGCTL register bits VbvalidOvEn and
VbvalidOvVal to disable the VBUS overcurrent detection.

This patch is derived from Dragan Čečavac (in the kernel 3.18.3
tree of CI20). It is very useful for the MIPS Creator CI20 (r1).
Without this patch, OTG port of CI20 has a great probability to
face overcurrent warning, which breaks the OTG functionality.

Acked-by: Minas Harutyunyan <Minas.Harutyunyan@synopsys.com>
Signed-off-by: Dragan Čečavac <dragancecavac@yahoo.com>
Signed-off-by: 周琰杰 (Zhou Yanjie) <zhouyanjie@wanyeetech.com>
Link: https://lore.kernel.org/r/1649964337-114337-3-git-send-email-zhouyanjie@wanyeetech.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>